Shasta winter camping

[Hemi03]

Hi I am setting up my 2017 oasis 18bh for hunting season here in south Mississippi where it can be 75 one day and 30 the next, last year we did get into the teens for few days. I don’t want to freeze up and bust pipes. I am using my fresh water tank and don’t want to put rv antifreeze in it because when I use the shower or will it hurt, I have other water for drinking. My water heater is gas can I put an electric heat coil and is there a chance of it freezing and busting. I hear the water lines will expand but I don’t know thanks for the help.

[Hemi03]

Anyone have any advice