I have personally never had a brazelberry. I took a look on the internets and searched for "brazelberry bush overwinter". I found the following:

In colder climates (Zone 5), you can overwinter plants in their containers by storing them in a sheltered, unheated area such as a garage or shed once the leaves drop in fall. In spring, bring them outside when temperatures remain above 25°F and place in full sun.

this document has lots of good info:

http://brazelberries.com/uploads/documents/BB_web_Growing_Guide_06_11_2014.pdf

Thanks! I need to add another garage to bring in all my "tender" plants!

I always need more winter storage for my plants. You would not believe the plants that I drag in and out again.

Could you bury the pots and mulch them with leaves and then pull them back out in the spring?