Michigan - BRRRRRRRRR!!!
If the battery is indoors at room temperature there will be nothing to worry about.
If your garage is attached to the house or heated that's probably still fine. My workshop is as low as 10 - 12 degees C. (50 F.) and never a battery problem on a Battery Tender.
If below freezing all the time in your garage I would bring it in for the winter.
Maybe E-mail Battery Tender with the question.
with this warm winter my bike never stayed parked more than 10 days at a time..at the most..hardly worth hooking up a battery tender..i wouldnt even consider it unless it was going to sit for more than 30 days at a time..and even then as soon as you start the cbr..it charges the battery back up to full if its even dropped a little bit anyway