We have four 5 week old ducklings. Three pekin and one Khaki Campbell. We're itching to move them outside since our entire house smells atrocious, and I'm tired of cleaning out their brooder so often. Temps here for the next week or so look to be mid 50s during the day and right around the freezing mark out night; I think the lowest is 31. Would they be alright to be moved out to their pen with a heat lamp at night? They haven't had a heat lamp on them for about 2 weeks, and they seem to be doing fine in the basement.