Camp Hpt water system

Hi everyone! I figured this would be the best place to ask this question.
I have a seasonal camp in Upstate NY. We use it from about April 1st until near Christmas time.
We have a 500 gallon holding tank that is filled by rainwater from the gutter. We use a on demand flowjet pump to supply the sinks. We currently have no hot water. We do have electric so we heat water in a pot on the stove.
When the weather is warm we have no problems and everything works as planned.
When the weather gets cold and below freezing is when we start to have issues. We burst the pipes once and cracked the solenoid on the pump another time. So once the weather dips we take out the pump and drain the tank and lines. Essentially we are back to bringing water from home in 5 gallon jugs.
I want to set up a system where I can have running water and hot water during the cold times. My thought was to have a 50 gallon holding tank inside the camp and a small electric hot water tank. If the holding tank was upstairs and the hot water tank was below that and the shower and sinks below both of them would that work? I could also get another pump and run a mini system inside. So I was thinking run a cold water line to the sink/shower, then run a cold water line to the hot water tank and then from the tank to the hot water side.
We could either leave the furnace on low when we aren't there in cold times or drain the system.
Thank you for any help or advice you can give me. I want this to work smoothly.
Matt

Speedbump will probably be along to give you a better answer, but I am thinking that you could use a small centrifugal pump with a small bladder tank and pressure switch that is fed from the 50 gallon holding tank. I wouldn't use the water from the holding tank to drink, as it would be susceptible to bacteria infection.

Are you wanting to put these tanks up high to get some pressure from them? You will only gain .433 pounds per vertical foot.

The Flojet, Shurflo and Delevan 12 volt pumps are great for your application. No pressure tank needed and they turn themselves on/off with water flow. You could plumb your place anyway you like and put the pump at the bottom of the tank so it has a flooded suction. Open a faucet and the pump comes on. A jet pump and tank like Phish suggested might be over kill for you unless you wanted to expand on this plumbing system later. The 12 volt pumps have a limited flow and wouldn't be very useful for two or more uses at the same time.