Winterizing - How cold can it get?

[Davanator]

I just traded for a 2006 Flagstaff 5r that is parked an hour away. I was wondering how cold it can get and still be ok if I have the lines blown out but no atifreeze in the lines. The heat would also be on and set at 60 degrees. The heat ducts are in the floor. Will it be ok for a couple of days with temps in the 20's or should I make the trip to put in antifreeze? Thanks,

[TheSasks]

It goes down to as cold as -35 or so here no issues.

[windrider]

If you left the furnace on 60, hope you have plenty of propane

[Davanator]

I will have the furnace on but it will be set at around 45 - 50 . My son was living in it while his house was being built but he knows nothing about campers so I talked him through the blowing out of the lines but the antifreeze is here with me so I was hoping it would be ok for a couple of days. This is our first camper that has an enclosed underbelly so I'm sort of learning also. Thanks for the info so far.