Nothing. They should be hardy for you. No trimming, no wrapping. Since our winters are more wet than freezing cold, any wrapping or mulching could lead to canker next spring. Leave them be, except to make sure that they don't dry out during the season. They don't need as much water, but they don't want to be totally dry.

Oh, BYW, snow is an insulator, so if we get a lot of it, that is not a bad thing.

It is optional for minis for winterizing I'm zone 5/b 6 Mass. Yes they are winter hardy when they come from a store I just winterize mine anyways if you opt. to do so this is how.

The weekend befor Thanksgiving you can if you want
Trim it down to 1 foot high into a dome shape then cover it up with eiter hay or dry leaves in a manner so that 2-3 inches of cane and leaves are still exposed and top it off with some medium sized sticks to hold the hay or leaves at very least let one inch of cane or leaves exposed. Pine tree brances work best to hold down leaves so they dont blow away

When and if it warms up in late Feb/safe is early March you can remove the sticks and some of the hay this will help em breath a bit better continue removing the rest of the hay late March.

There will be some odd looking small canes coming out of the ground in spring. Minis are own root growers there not suckers they will catch up and flower but do trim off dead looking leaves and cut back blacked parts of canes if any.