Hi Leo, it is not ideal to have new basals starting at this time of year, but unfortunately it's bound to happen when the fall is this nice. I just finished pruning my roses and winter-protecting them and they all had some new growth with buds that was disappointing to cut off.

Given that Prairie Peace is a hardy rose, I would say that you should just stick to your regular mulching regimen and if the new shoots don't survive the winter you can just prune off any dead ends in the spring. If they are going to harden off and survive, it will not do any good for you to provide extra protection now. On the plus side, the new shoots of a young own-root rose should be nice and whippy and flexible, and easy to mulch over.

Anyway, if you do lose these shoots, your older shoot(s) and the own-roots will pick up the slack in spring.

Hope you can post a pic next summer... it's not the most common rose. :)