Cold Weather Questions

[IchLiebeBier]

Hi all,
We're having a house built and when we sell our current home, we may have to spend a month or two in the camper, depending on the move out/move in timeline. Unfortunately, this may be in the Dec-Jan timeframe. Location is Northern Virginia.

Our camper has an enclosed/heated underbelly (meaning furnace air blown into the underbelly which only has coroplast bottom).

So I have a few questions for you:

1. Given no changes to the camper, how cold could it get outside before I need to worry about freeze issues. I understand the water hose issue and may get a heated hose just to be safe.

2. What steps can I take to be safe if temps get down into the teens (sustained)? I'm thinking skirting and possibly adding tank heaters, but I'm worried about freezing water lines. Do you think I need skirting if I have the enclosed underbelly? What about skirting with a small electric heater blowing underneath?

3. If anyone knows my camper, how many vents blowing into the underbelly are there really? Or is it just a hole cut in the floor to let the heat in?

Thanks in advance.

EDIT: I know average temps show in the 20s, but it does get into the teens sometimes, depending on the winter.