As long as you have unlimited propane so you can keep the furnace going full-time you should be OK. Many people get that tin foily insulated stuff and cut to fit windows in the bedroom to help keep it warm. If you install skirting and insulation that will hopefully keep the tanks from freezing. How do you plan to keep the water tank full if water to the tap is frozen? Best advice is to talk to others in the park that are fulltiming and follow their advice.
2007 33.5' Arctic Fox Fifth Wheel used for full-timing for several years--now sold
2011 Hideout 23RKSWE that we now use for poking around local parks
2007 Chevy 3/4 ton diesel with Prodigy Brake Control