I only triple thick (well actually Rustoleum Clear)
when absolutely necessary, and after lessons learned,
I only keep a sealed glass in a pretty much climate
controlled area. I have never lost a glass in cold/warm
storage that hadn't been sealed..

Yeah, when I have sealed, it's pretty much a must to cover the windows and any other
animated areas. I got good at it, but never was able to leave a picture perfect clearness
in the windows..
In my younger days, I was thinking the same way to preserve a mint glass by sealing
and then had in storage here in N.Y., and dammit, what a mistake..
I highly suggest not to seal a mint glass.
I just read the upper post. Yes, on a flaky glass, masking is a no for me. I covere the
windows with a slightly oversize piece of lath (or whatever) over each window, and weight
it down with something like a lug nut on each. When spraying, sprayed directly above (on top) of
the windows to take away chances of the spray sneaking under the lath. Then within
a half hour or so (while still tacky but not runny), I removed the lath..

Just to note: I wrote the previous post before reading this one..
I use to use tape, but you need to be dead on and still found once the
spray dried, it still could cling to the paint and the tape, so that's
when I went with the lath and always made sure that I removed
the pieces well before the clear had dried..

I say very wise move. Why tamper with something that's
been mint for 40 or 50 years..

I can speak for myself that for many years I've had/have many EM pins stored in a barn with no climate
control, and as long as they haven't been sealed (with a spray), I've had no issues. I'm in Upstate N.Y.
I will add that a dehumidifier would be a huge plus and absolutely suggested. It's always nice to have
machines in an at least somewhat controlled climate, but I myself haven't had any issues. With sealed
sprayed glasses, that can be a different story. I'll never spray again. I clear vinyl them when needed..
btw: what titles do you have?

If you're not going to have them set up to play (or at least in the Winter), it surely wouldn't
hurt to bring the backglasses inside in a safe spot..
My storage barn is fine, but in the basement before I added a dehumidifier, at times I
would notice a white powder like substance on the playfield. It was because of the humidity.
I think your garage would be okay, but putting in a dehumidifier would be a plus and then
be able to see how much water it does collect.