In the snow line or nearby?
What type of heating, and power?
The aircon unit won’t heat but electric blankets, cheap fan heater, or electric oil filled radiators work well. If off grid, most go for a diesel heater.
Pipes will freeze but usually ok by mid day. Even if you lag them, the hose from the tap to the caravan will freeze when it gets cold.
We go each year and cold isn’t an issue.