BA have issued Customer Guidelines for this one.
Airports in scope:
ABE, ALB, AVP, BDL, BOS, EWR, HPN, JFK,LGA,MDT, MHT, ORH,PHL, PIT, PVD, SCE
If travelling on 13 February 2023 and the flight is not (yet) cancelled, you can call up and get rebooked on alternative dates up to and including 15 February.
If the flight gets cancelled - which could be late on - then you get further cancellation protections, so the above is really for those who don't wish to venture out tomorrow. This Guideline was released at 08:00 hrs this morning (but was issued on Saturday), I don't know if it's also online via a Disruption Menu, but either way, calling up should do the necessary.