We carry two gallon jugs of water and don't use the trailer water at all. Many food stores have Glacier or other brand of filtered water and for 25¢ a gallon, using the trailer water system just isn't worth the hassle. For the port-a-potty, we use an old quart detergent plastic bottle which does a better job of rinsing the bowl than the built-in flusher. Plus we can dump the unused water out and not worry about freezing the water tank on the PP. We dump the PP every morning.
If the weather is above freezing and you do hook up your water to shore utilities, be sure to run the water before hooking up. Some people keep a jar with bleach in it to sanitize the faucet. Don't forget that animals like water, too and may have just licked the faucet.Filling my half gallon jug at one park, a couple of insects were sheltering in the faucet opening and if I had just hooked it up to Homelet... Not to mention that many water faucets are just about the right height for a dog to lift his leg against. Also get a water pressure regulator. Luckily, we were sitting outside Homelet when we heard water running. Park water supply pressure varies greatly. Hooking up to water in the winter is not a good idea because your hose will freeze.
There are two excellent articles in this blog dealing with winter:
http://www.fiberglassrv.com/winter.html
http://www.fiberglassrv.com/winter_camping.html
The first one is on winterizing and the second on winter camping.
Don't forget that heating the inside of your camper to keep things thawed will not work when driving to your destination. Your camper and tanks will be exposed to 50-60mph winds on the highway, and if the temperature is below freezing, well.
As for hot water for instant coffee, tea, etc, We heat a teakettle and then pour it into a Stanley 2 Quart thermos bottle which keeps it hot all day. We do this at home, too. Use a hot mitt or glove to protect your hand from the steam coming back out the mouth of the bottle.
Just a few hints from our experience. Welcome to FGRV. You are going to make many happy memories.