The past few seasons they closed on November 15, 2007. In regards to cold temps it depends on what you think is cold. It is not unusual for the mountains to get into the mid 30's to 40's at anytime during the summer. I am most comfortable in the 20 - 50 degree range of temps. But some folks think they are freezin to death at 60 degrees.
The manager of Table Mtn, Lake & Mtn Oak is Daryl Walters. He is a very nice man. You can reach him @ 3526 if you would like to know for sure when they are planning on closing up for the season.
I hope this helps...