The RCX chipset is housed in the base of the scope.
Based on personal experience, these chipsets can be sensitive to the cold.
When I called Meade on my issue: At 18f Autostar froze up and RA would not move.
They told me that it's a known issue with the computer chips they use, and I returned it to Meade for a fix, under warrantee.
I should point out that by the time I got mine back from Meade, it was to warm to duplicate the issue. However, the next winter I had the same problem.
There is/was an outfit in Canada that replaces the chips, http://www.nortek.on.ca. However, a quick look at the website no longer shows the service as available. It might be worth a call if you are so inclined.