no heat!

There is a 'sail switch' in the intake air flow path and if the intake is blocked by snow or otherwise, then there is insufficient air for combustion and the valve that controls the flow of propane to the furnace will not open. Also, if the blower is running, but slow than normal due to low voltage or worn bearings, same problem will happen. Also, when the blower comes on, you should hear the ignitor clicking within about 10-15 seconds after the blower starts, if not, then either the sail switch or the propane valve inside the furnace is not working.

you have to check things out systematically.

1. do you have propane it the tanks?
yes then
does the propane stove light?

yes good.
then you have pressurized propane in the system and I would start looking at the furnace.

even though it comes on and runs.. if the battery power is too low.. it will not blow hard enough to make the sail switch in the heater make contact and turn on the propane.

Do you hear clicking after the blower runs for a min or two? if so that means that the igniter is working and trying to light the furnace and the sail switch is making contact..
I would try to re-seat the connectors on the furnace maybe one of them is not making a good connection and preventing the propane valve from opening.

remember that portable heaters do not heat the basement.. and you will have frozen pipes. I would winterize first before you get into additional trouble.

I can't see how it would be the thermostat.. as it is signaling the furnace to come on.. so it is working.

Since this is Sunday and you may not have access to a thermostat or you do not do your mechanical work (I don't). Got to Walmart, Lowe's or Home Depot and get some small electrical heaters to heat just the room you are in. Also, get an electric blanket or two to help you keep warm while sleeping or sitting in the 5th wheel watching TV.

I have a couple of the 12v throws in the RV so we can use them with the battery and not turn on the generator if we are traveling.

Good luck. Hope you are able to get something today. If not the above, then maybe thermal long johns or sweats or both.

Sounds like you have a bad thermastat.