Joanne,
Having done many years of winter caravanning in ice and snow the following points are important.
1. To avoid condensation never switch your heating off, even on going out for the day or at night.Your caravan will always be nice and warm.
2. Unless there is a strong wind blowing leave one window on night catch and roof light on night catch for air circulation.
3. Make sure you have if possible two full gas, or nearly full, gas bottles when you start your holiday.This is because on a lot of sites, even caravan club sites,the high demand for electricity can cause cuts in supply during periods of high demand.
4. If your caravan has an end washroom take a low powered electric heater with you and an extension lead to heat the washroom in really cold weather.This is because blown air heating is not very efficient when the temperature drops near to freezing.
5. Make sure you have winter covers for your fridge vents. These are to be used if the daytime temp drops below 10c.
6. If the temp drops to freezing leave a couple of kitchen cupboard doors slightly open at night to let the warm air circulate to your water pipes.
7. Cover your water container with insulation such as hot water tank laging. Also bring your pump into the caravan at night.
8. Empty your waste water before it goes dark. If a small amount freezes during the night it does not matter.
Please do not be put off by all this advice.It is a wonderfull feeling sitting in your warm caravan and seeing the frost or snow outside. I assure you once you have done it you will do it again.If you have any questions just ask.
Oh nearly forgot, if possible leave your handbrake off and chock your wheels so they will not freeze onto the hubs.
Enjoy winter caravanning, dare I say it the real way to caravan!!!
HAMER