I don't have a complete solution, mostly because I don't think you need one. I also don't think your biggest issue is going to be either of the two you've mentioned.
To control chem temps, get a instant read thermometer and large thermos. Fill it most of the way with cold water and then add warm water off your stove until you hit your temps.
Since you're shooting 4x5 frames, they'll be rather small, not the rolls you usually have when developing 120 or 135 film. For drying, get a tiny light tent, cut out the sides and replace them with mesh. Get a glue gun to glue a few clips to the top for holding. That should keep dust and bugs out, and if you go too big with the mesh holes and stuff starts getting through, just toss another piece of mesh on them when drying.
I'd say your biggest issue is probably going to be finding enough warm enough water to wash your sheets. Cold (40-50F) water will not wash your fixer out properly, and making enough 75F water to wash it properly (multiple washings) will probably be difficult. The ground water you often get at camp sites also tends to be extremely hard, consider a washing agent.