Bella has long sleeve cotton pj's with a singlet underneath - then in her sleeping bag and then wrapped with a blanket and a blanket over the top that is tucked in firm so she cant wriggle out. We have our reverse cycle on pver night and its on between 20 - 24 as it gets to -2 here over night and our house is 40 yrs old and have gaps that can get drafty. She usually gets her arms out and I tuck them under her top blanket. DD likes it warm and never wakes over night (unless sick) so Im not changing!!
If the roomis cold during her day sleeps she will wake after 20 mins - but if I have the heater on she will sleep for 1 hr +.

HTH Kate