I store my tackle on shelves in the garage during winter. My question is, should I leave my 3600 boxes open during winter? So air and water can get in and out to prevent rust. Will this help?

Drill some small holes in them to allow for air flow, helps during the season too with rusting and deterioration.

I keep most of my tackle in the boat covered. If the lake is not frozen I am using it. Last winter not so much. The previous 2 years the lake never froze and we fished all winter.

save all the packs of descant you get and throw them in your boxes