They certainly look like rufa. It is probably the most cold tolerant of any bamboo species, clumping or running (it is a clumper). usually listed to zone 5 (-15F) and is fully evergreen. I have not had experience with it at those cold temperatures to confirm but at least one professional source indicates it rebounds well from any environmental damage. Or marauding pandas. 🐼

Mine burn when temperatures drop to the zero range and the plants are slow to recover, but I would wonder if the ones shown are a hardier cultivar since my guess is that you've seen similar if not lower lows there in SE Michigan. Mine will possibly send out new leaves on the damaged stalks, but it will take a while for the roots to produce new stalks which look full again.