Good pointer PeterP. Blacking out on an LCD isn't that bad, really. Just give it time to warm up and it should be fine.
It is my understanding that getting the air out of the ziplog bag isn't an issue. Unless you mean "get rid of all the indoor air". That matters. I just take the bag outside, open it up and let the warm air rise out. After a minute or less I assume the air is all low-moisture cold, outdoor air. I guess that might keep the camera from warming up as fast, but there is little risk from moisure.