My, haven’t Putin and his buds gotten belligerent. Given the bluster I think this is nothing more than false bravado. If they do anything it will be very measured, as opposed to going into say Poland. The fact this has really gotten under their skin and there’s little they can do to directly punish Poland (other than turning off the lights) is apparent by their incessant chatter since the deal was signed.
They could also turn off the heat this winter, do not underestimate the stupidity of Putin.