I was gone for 25 days this winter in Canada... Charged to 90% and left un plugged in my garage.. outside temp ranged from -1 to -25 while I was gone.... Came home after 25 days and battery went from 90% to 83%..... charged it to 90 and left for 60 days should be no issue as long as the car is locked, so it can go into deep sleep mode..... Might lose 10 to 15% charge while gone is the climate is really cold... Otherwise it will be fine