i stick hot, not boiling water over the screen door seals and dont worry about the lock as it remote central locking. Before everyone starts, My dad has done the hot water trick for 40+ years never had any issues even when he lived in st petersburg!
I guess the thing is to avoid getting the hot water on the freezing glass.
Summat on the telly last week was saying washing up liquid in the locks will stop them freezing
A mate used to have a problem with frozen locks in early hours of morning after coming off night shift.
Rather than going back into work to get some hot water he used his own method - urine applied directly from the "container"
Paul H