Your lift motor is failing, and many have seen it get worse in low temps.
Mine is the opposite, it just flops back down in summer but works great in winter
There has been a great deal of discussion about this at AW forum and some have fixed bent hinges or replaced lift cylinders with some success.
Ultimately it's the motor though usually.
The typical latch problem I've heard of is that it won't lock the trunk winter.
You can tell if that's happening by just trying to lift the lid without "opening" it - if it lifts right up the latch mech needs to be replaced.