I have a bedside safe which is foam lined, but mostly open space inside. I keep an XD in there. I have normal A/C. It keeps the house about 73 on average. The only negative is it is basically inside my bathroom. When I get done with this, I think I'll turn the fan on as it felt really moist in there this morning!
So that is pretty bad, right. I use good lube. I look at it weekly. I have never had a single corrosion issue.
I guess I'm saying...keep it in your house, at hand and lube it as often as you need to to allow it to survive the envionment. A Glock should be way better than most.
If it matters to you, I use Weaponshield on all my handguns and have NEVER had an issue. I have used the original FP10 since about 2000 and moved to Weaponshield when that ran out. These are the best CLP's I have ever used. I see no reason to change. I have stored guns in a foam gun case for a year before I knew it was "bad" with no issues.