Hi Worzel If youve got a old sleeping bag try putting your water bottle in that and if you can put that in a large plastic bag thats even better, You can if your not going to use your pump at night bring it inside fill your kettle up for the brew in the morning and fit the pump when you need it, But through the day wrap it say in an old towel just to keep the cold out.As for heating we went to scotland for six nights over new year snow on the ground all the time put your gas fire on for a good hour to warm the blow air pipes then turn off the gas and switch to electric, ours was on for the full six days and nights no problems, you could even invest in a small electric fan heaters for topping up but dont leave them on at night