I have the same ish kind of setup in my shed and ended up making a box out of styrofoam with some ventilation holes to let them heat that up and keep them isolated from rapid changes in temperature. I have some Mac minis from 2012, a nice and a router running along quite happily in there :)

Just copy the docker compose file into portioned? It’s what portainer calls “stacks”, same thing. Also an alternative is to just spin up the docker compose directly on the host and portainer will pick it up, it just can’t be directly managed from portainer.