That's a bummer. If I were you, I'd definitely leave the lights on. I'm saying this because in only 2 days your plants won't have enough time to slip into revegging and even if they do, this will only add maybe max 1 more week to your flowering period and will only increase your yeald.
Actually, there's a method proposed by a member that I'm going to try out soon enough. With 2 weeks before harvest, switch to 18/6 or 24/0 for 2-4 weeks. This will cause a revegging. The plant will grow alot in this stage. Switching back to 12/12 and letting her finish will guarantee double the yeald now.
maybe, if you got the time and space, you're willing to try it. Even if not, light is better than darkness. (It's even recommended that in the last 2 weeks you go to 14/12... this will assure a larger yeald).
Expect your plant to grow a bit if you leave the lights on for 2 days.