Your ladies should be fine. A few days at freezing especially with their size is probably not going to do any damage to them and it does make for better smoke. I like mine to have a few days (more is better for best results) of that cold before harvest. So far only into the lower 40s but 3 weeks to go on one set and 2 months on others. Mine can still come inside if it gets to cold. If you trim/top them (so one branch becomes two) they will not get so high and they can still fit through the doorway.