I went ahead and purchased the CM-7777HD. I installed it and right away started receiving one of the stations I had lost when the weather turned cold, so I'm encouraged. I also notice that the signal strength indicator that my Samsung tv gives me for each station shows a much stronger signal for each station.
The real test will be when the weather turns really cold again. The day I installed the new amplifier, the temperature was 58 degrees. We'll see what happens when it the temperature drops below 34 degrees.
I have no doubt that your signal booster is not the one causing problem. When the temperature drops below mid 30s you will see a few channels disappear again.
At this time I can say for sure that your matching transformer (balun) is the culprit.
The bad news is that you will not be able find any replacement balun on the market which can fix the disappearing channels.
A balun consists of two (insulated) copper wires winding around a ferrite magnet core. In theory, it would last forever but in reality, the ferrite magnet core loses its property when the temperature drops and the result is that TV signal passing through it would loose its strength.
The good news is that there is a way to resolve it: You will need to move the matching transformer to a warmer place, like under the insulation or inside your house. I chose the second because my antenna is inside the attic and right above the closet.
You can use either the "cylinder" or "block" shape indoor balun. (The "block" shape is the one came with older TV to attach bow-tie antenna to the back of the TV.) I chose the "block" shape matching transformer because it can be attached directly to the signal booster. I made two long lead wires out of RG-6 cables by striping about 3/4" at each end of the cables to the expose the copper cores and attached one ends to the antenna and the other ends to the balun. Please note that you must use shielded cables to connect your balun to the antenna.
So far my TV signal is really stable even the outside temperature has been down to low 30s at night.