you must have a lot of moisture right there, maybe from snow or something? if so keep it clean. another option would be to adjust the down travel limit so tha tit stops just short of teh floor. you won't get a weather tight seal then, but at least yor door won't freeze down.

BTW, if you opener kept exerting force trying to unstick the door then the up force was improperly adjusted. you should be able to grab the door while it is opening and it should immediately stop.

Great ideas thanks, I'll try those.

I work in refrigeration and the worse thing to do is to leave a gap... the moisture from the house is going to try to escape from that gap and accumulate ice as it reaches the dew point (when the moisture in the air condensates and freezes).
I would suggest to try greasing the gasket with some sort of grease (vaseline if it doesn't affect the material), otherwise the real solution is to install an electric heating cable.

luckyluc, most folks don't leave the door from teh house to teh garage open any longer than necessary. there won't be a lot of moisture coming from teh house. even if it did, he has ice right outside the door and it ain't going to make it any worse.