First, DO NOT STORE THE BATTERY FULLY CHARGED! Permanent damage will result. Store at approx 60% of charge.
Definitely store indoors away from freezing temps.
Now, the tricky part. The BMS in the battery is a parasitic drain, and not easily disabled. VERY, VERY small drain, but unfortunately, all of it on just one cell group. Over 2, or 4, or 6 months, this can totally drain that cell group past the point of no return and totally destroy your battery, requiring replacement or rebuild.
Ideal solution would be a variable charger you can set to a 60% charge, (expensive, and you would ideally also a BMS with a controllable balancing voltage threshold), next best do a full charge then ride down to 60% every couple months, (not super feasible in winter, and that controllable BMS would help), or, every couple months charge for approx 1/2 to one or more hours, ratio of amp rate of charger and total of battery AH rating, and a judgement call. The fancy BMS would help here, too. But, they are rare, almost unknown on commercial bikes, most folks do not understand the value, may be common some day but not today.
Then, when riding season arrives, do an overnight charge to give balancing function time to bring the low cell group up to full charge.
You can get more data on best procedure for your individual case by partially disassembly of battery, and DVM testing on the individual cell groups at the sense wires after removing the plug from the BMS, but most folks will not dig that deep.