I've kept mine in a hard case in my trunk / garage / basement / BOL cabin all not climate controlled. Most newer bows are made of composite materials that are very dimensionaly stable, won't change shape due to humidity and temp changes. I set the pins on mine 4 years ago and they are always on the money, be it August or December, well except user error of course.
Keep the string waxed, when it starts to fray get a new one.
I'm in MI also, so similar climate.