As for the plant you plan on chopping, no prob at all. As for the other girls, it very well may set them back a few days, maybe a week. Im dealing w the same thing right now and have as well, in the past. I know of one person who lost power for 5 days in the middle of flower and it set them back 2-3 weeks. My were in the dark for 48-52 hours and should be done tommorrow....and i really, really want to cut them, but i think i may have to wait until mon.....sigh....so, know it wont affect them other then possibly extending your flowering period by a few days.