Node Red and high availability k8s or k3s

I'm running NodeRed in Docker for the last year, everything is good life is very simple.
But the question is how to setup a High availability system with multi PC simular to K8S or better simple K3S.
I have x3 Slim Lenovo PC with Intel I3 4G ram 250G SSD, and one powerfull server x2 Xeon 8 core CPU and 64 Ram. Anyone running Docker containers in multi PC mode? Any guides?
From a practical point of view, I need something to run Node-red or other docker containers 24/7/365.
and with possible powering down one PC in case of hardware repair or self-healing like Kubernetes.
I can't find any practical installation guides.

Anyone running Node-red off cloud on local hardware with K3S or K8S?

Here is the K3S info: