The lack of issues can never be guaranteed, but if you backup everything in your .node-red folder (or whichever folder is the one with the flows and settings.js etc) except for the node_modules folder. Then, to install in the new system, restore all of that to the new .node-red folder, cd into that folder and run npm install
which will install the extra nodes you need, and will take a little while on a low power pi or similar. Then start (or restart) node-red.
You can install Node-RED on your server then have the ability to copy the whole instance to any internet facing or non-internet facing machine. Then from your server (internet facing), you can update/add nodes for that version of Node-RED inside the editor. Then copy to the non-internet facing instance (folder/subfolders) to your working instance.
If you are just copying the whole set of files across, make sure you are copying to the same OS and version, hardware, and nodejs version. Otherwise you will probably have problems with any nodes or modules that include compiled code.
For this, as Colin says, on the new device, make sure you run npm rebuild on both the outer folder (where Node-RED is installed) and the inner folder (which is your useDir and where most nodes are installed). If using UIBUILDER, also do a rebuild in the uibRoot folder.