If you're putting the Wemos into deepsleep there shouldn't be any self-heating, so the placement of the sensor shouldn't be an issue. Just my 2p worth.
Much worse I would think.
I've had issues with the M5stack basic when trying to shut down the screen - more to save the screen than to save power since all my platforms are plugged in (I'm too lazy to work out how to get them to a point where they would run off battery and too lazy to change batteries anyway 
). I can get the screen to turn off but there seems to be an issue with waking it up again. I'll work it out eventually, not really top priority for me at the moment.
My Pi3 also has a screen on it (3.5") - one built into the case. I did run a desktop on it for a while but it takes so much out of the Pi that it really isn't worth it if you want to get anything else done. Now it just shows the default command line. I could remove it but until recently, I needed it up 24x7 so never quite got to it. It now only really runs the Ubiquity Wi-Fi controller software. I don't actually need that 24x7 but I leave it running anyway and I couldn't get it to install under 64bit Debian on the laptop that is now my home server. MondgoDB playing silly whatsits.
It takes time to wake and join the WiFi. In that time, the ESP heats enough to affect the chip.
All I'm saying is think about placement. That particular hat is a complete failure and I don't use it. It was cheap and I brought it along with some other hats in a sale a few years ago. As you know, I won't use DHT11/22 sensors anyway as they aren't accurate enough and drift over time.
No I don't, it's a headless setup. It runs the latest version of Pi OS Lite (no desktop) with MQTT and Node-RED (with Dashboard) installed. Here is a screenshot of it's resources:
I found this: Raspberry Pi 2/3: Chromium in Kiosk mode a while ago and wanted to see if the Zero can handle it, but didn't have time for it yet.
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Thats why i read the temperature before connecting to the wifi. Its the first thing i do in the sketch before starting the wifi after a deepsleep.
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Would be interesting as that would be the possible use case of the case above.
But as i said above i strongly suspect that it will struggle with anything but a headless setup.
OK, that makes sense, I agree that a Zero can run node-red and the dashboard server end but here the pi has a local screen and I believe that the idea is to run a dashboard on the screen, in which case, to run the node-red dashboard, it would have to run a browser, which I think would not be practical on a Pi Zero.
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Ok I tried the kiosk mode that I had mentioned above and it worked even at 1920x1080.
It's not super fast of course but it's ok.
The smart wall mount only has 320x240...
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I'm using this on an android tablet and it solves a lot of issues for a dedicated display.
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Does anyone have experience with the Nextion displays? (From the same folks who do Sonoff.) It has been a while since I looked at them, but IIRC the idea is to off-load display generation and human-machine interface to a co-processor in the display, with just a relatively low-bandwidth serial connection to the SBC. You would not expect the flexibilty of a real web server, but for the sort of thing being discussed here it might work and be fairly inexpensive.
I bought the Nextion NX4832K035 a few years ago and connected it via serial to a Wemos D1 Mini.
It's fun to program the display (they have an editor for that, where you can design the UI and stuff). Some buttons on my Nextion Display then sent specific codes to the Wemos (via Serial) and the Wemos made specific https requests based on the code it received - worked well!
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Thanks, I'll look into it, could be just the ticket.
I don't, but I remember that Pete Scargill has covered them. Not very up to date but it might help.
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Tried it on an android 5 phone. Works good but doesn't solve the problem of the phone apparently going to sleep and turning off wifi. There was a lot of activity on my dashboard while my wife and I were in the hot tub and an Amazon package was delivered, these are non-events, but I have them enabled for testing/troubleshooting at present, when I came in the phone screen was dark and I had to relaunch WallPanel from the home screen to see the dashboard again. So basically it don't work for the task.
A step in the right direction but its still not there, as you need multiple button/screen pressed to see the latest system status.
Have you checked the settings ?
You can disable sleep and setup motion or face detection so the screen comes on automatically.
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I thought I looked through them all, I'll check again, found it. I see if that solves the problem. Takes hours for the screen to go "dark" sometimes it wakes up when I touch it other times I need to hit the "power" button which wakes the phone, but its at the home page instead.
I hope to run it on our old Nook HD+ tablet which I've installed Linage on, it doesn't have a camera so none of the motion detection settings will be useful, but if I can't get it to do what I need on this newer old phone, doubt it'll run on the Nook
You really should let the screen go off if you can or at least make sure that the screen display changes regularly so you don't end up with burn-in.
The ideal would be to couple the display with a wireless PIR or similar so that it was turned on automatically as someone approached or went past it 
I'm using an old phone/tablet that will either work for this task or end-up in the dustbin, Screen burn-in just don't matter here. There are some "screensaver" dimming features I'll investigate if it works.
I got it installed on the Nook and left both running for a few hours, when I looked over while typing this, both had returned to the "home screen", and as I typed this last sentence the phone screen went dark.
So unfortunately it seems that Android has deep in the bowels features built-in that prevent its devices from being useful for anything where you are not fondling the device or connecting to cellular services.
You can use Tasker to keep the screen on. I find it still goes dim after a while but you just have to touch it to restore the brightness.
Chrome does crash occasionally, once every couple of days maybe, at least I assume that is what is happening as it returns to the home screen. I have a shortcut on the home screen to take me to the relevant page so that isn't a major problem, for the way I use it anyway.
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The blanking of the display while not desired and annoying, is not the problem, the real show-stopper is eventually (a few hours with my old phone and Nook tablet) it "crashes" to the home screen and the WallPanel app needs to be restarted again reloading the entire dashboard instead of just refreshing it.
