Something I did was to put a 30”x30” powerful belt driven gable vent with a nice decorative front screened grill (bugs) up and inside the garage (and attic..I did 3 total) I attached a hygrometer AND thermometer (all one unit) and a snap covered on off switch for when belts need changing and I don’t want to lose fingers. The hygrometer is set for 37 percent humidity (in Mass you would be safe going with 50% to keep it from running all the time) and the temp was set to 140/80F. In the summer the peak of the garage hits 140F by 7am and either the humidity setting or the temp sets it off. If you are actually trying to use this to cool the garage you can set it for lower temps but you are going to use a LOT of electricity since the heat will constantly be high up near the fan. I would recommend putting window or wall mount fans at work level and have switch to flip them on when you are going to be in there. They are cheap at $120 each for professional units and will NEVER wear out (until your home burns down and they melt…or maybe that’s just me…and the fire was caused by something installed long before I bought the house). So that’s a thing I did to resolve both moisture and heat issues. The two in the attic of the house, Mid point and North end, were quiet and smooth operating and I never had a repeat of mildew and never overheated or overworked the air conditioning in the Summer. In 2006 this was $480 done professionally but that’s pretty meaningless now. What you are talking about with my recommendations will run about 550 DIY$ these days for the single fan and a couple window fans at level.