For your winter months put each tire on a block of wood. To prevent tire root.
Put each bike on a battery tender.
Fill the gas tanks.
DO NOT START BIKES IN WINTER. There is no benefit to doing so and it can foul plugs and create condensation in motor.
Throw a blanket over them and let them sit till spring.
By the way you don't need to heat your couple cave cause of the bikes. Cold will not hurt them. I live in Minnesota and the lowest my garage has every been is Zero and the bike is just fine.
Please add your state and model of bike you have. Click user CP @ top of page and then far left click edit signature. Thanks