Re: Need some ideas for water system?
Personally I would want to put the pressure tank and HW heater in the crawl space if at all possible. First it would save space in the main cabin and also if it starts to leak there wouldn't be anything to damage. It looks like the cabin is not that old and I would guess that you may have french drains running around it that outlet somewhere? If you are only draining a couple of times a year then you should be able to let it run into the gravel. The other option is to run it into a sump hole and have a small sump pump to pump it outside. After your first winter you will see how cold it gets in the crawl space (put a high-low thermometer in it). I think they make insulated covers for pressure tanks and you could probably put a heat tape on it if you need to. The other option is to make a small insulated box in the crawl space for the tank and hot water heater with a thermostat hooked to a heater to kick on when the temp hits 35 degrees. If it is insulated well then it wouldn't need that much heat.
If most of the crawl space is below ground and it is sealed up pretty good, I would think that it wouldn't be too likely to go below freezing until it got really cold. In other words you would likely be good for deer hunting season, but maybe not Jan-Feb. Your first winter will tell the tale.
Traditions only last if you pass them down to your kids!