To address the OP, it is pretty much an impossible scenario, although I'd prefer the term "extremely improbable". It's probably more likely that you'd have some kind of inadvertent flap retraction (due to crew action) than have the system act on its own. But even that is pretty damned unlikely.
Many flaps don't move that quickly, so in fact even with retraction starting at V1 you might still have some portion of flaps left at Vr. In terms of what you would/should do: I'd suggest that the time required to identify the problem would be such that you'd be up and away long before you even considered "uncommanded flaps" as a scenario - which means you'd be climbing out at your "usual" AEO speed, and the only question is whether anything would happen before that point.
My own guess is that not much would happen; your rotation technique will be the same as any other takeoff, so the peak AoA will also be similar, so there's little chance of a stall (unless LE devices move uncommanded - that's a whole new scenario). You will get less lift at the alpha you get, so the takeoff will be more sluggish in terms of initial climb, but unless you're obstacle limited I doubt that should matter much.
You'd be better off doing the what-ifs for the cases which have happened, though - one of those would be far more likely to reoccur, and having thought THAT scenario through may well repay you at some point.