I looked at your profile, a 37' Harney indicating it is an older coach.
You indicate you will not have full hookups but this usually implies no sewer. If you truely will not have any power then you will have to rely on your generator as primary and propane as secondary. Even if you used the propane you'd have to run the generator every 8 hours for ~1-2 hours to charge the batteries, maybe more depending on other usage.
First thing I would do is check all the seals on the basement doors to make sure they are tight. Also look at the front & rear chassis areas as manufacturers don't usually seal these areas good. Buy some spray foam to seal these areas.
I assume you don't have heat pumps in your AC units. If you do have them and the outside temps are above ~38F they will produce have, as it gets colder they quit working. If you decide not to use the AC units I'd put covers over them and seal the with venting to prevent air intrusion. If you are running a generator you could use small cube heaters in the coach.
I would buy a remote temp monitor and install in your wet bay. Usually a propane furnace will have ducting in the wet bay to keep it warm but it can still get cold enough to freeze thing. If you are running the generator you could put a small cube heater in the basement, I have bought a thermostatic plug that will turn the heat on at 38F and off at +55.
If you are going to be parked in 1 spot for a long time you could buy some bales of hay or straw and stack around the base of the RV, this will help keep the basement warm and prevent blowing winds.
In March of 2011 I moved to Northern Michigan, the UP, and lived in Wakefield. There was 2' of snow still on the ground and we got another 2' of snow in April. Temps would drop down into the signal digits sometimes at night, many days in the teen's. I had use of 2 20 amp outlets, that's all. I kept 1 cube heater in the basement and 1 heater in the LR. I would monitor the basement temps as above. Sometimes when I woke up it would be 30F in the bedroom. I survived but it wasn't fun >>> But I would do it again.
2002 Monaco Windsor 38 PKD
2005 Jeep Grand Cherokee w/5.7 Hemi