Winter temp

Somwewhere in the 20s.
It was 5 at the house last night. I am going camping in the RV in a few weeks.

In all reality, 32 degrees F. If you had no heat in your camper and it sat in 32 degree weather for a year, the pipes would be frozen. The only thing that delays the freezing process is how well insulated your camper is and much heat can be generated to offset the 32 degree temperature before that 32 degree temperature penetrates and starts freezing things up.

For each of us, it's a gamble how much into the 32 or below temps we travel. To be absolutely safe-absolutely!... Winterize when temps are 33 degrees and you'll have nothing to ever worry about.

To be comfortable, do it when temps are 55 so you won't freeze your fingers getting wet! :B

Impossible to say since it varies depending on a number of factors:

1) The actual construction of your unit
2) The temperature
3) The length of time at below freezing temps
4) Possibly the wind conditions.

But far below freezing in the teens or lower is an instant cause for concern. Mid twenties would have to stay at that temp for a longer period of time. And so on.