I would check fuses and circuit breakers first to make sure none have tripped or blown that are associated with the furnance
Make sure the batteries are charging...some control units require 12v power and if the batteries are low will not work.
Check wiring connection to make sure they are not loose or corroded
Find a mobile RV repair technician in the area, check with the dealer and manufacturer they may pay for the service visit under warranty due to your circumstances.
Think about getting a couple of portable electric heaters until you can get the RV to the dealer.
Our furnace can be removed through the fresh air vent inside the RV. Make sure the gas is shut off and the gas line is capped. A friend was burned, the repair person remove the furnace and failed to tell her he had not capped off the line. He was gone when she returned to the trailer. She went outside & turned on the gas so she could cook dinner and as she got back in the RV there was an explosion.