Well you've certainly gotten them off to a good start! I don't think you need to be all that worried in your zone 7. Your winters are milder than mine and I don't do much of anything to winter protect my minis in the ground. Most minis are on their own roots so even if they die back to the soil they usually come back from the roots anyway.

I wouldn't use the bark mulch. I think if you have a supply of leaf mulch that would work just fine. And don't worry about those branches. They're stronger and more flexible than you think. Roses are very tough and hard to kill, even the minis!

I don't know when your first frost date is but you want to wait until after you've had several HARD frosts before you do any kind of winter protection. The roses should be fully dormant before you winterize them. They'll start slowing in growth as the days get shorter and cooler but they don't go dormant until it gets really cold.

Thank you for the information. I would have started way to early.