I would drop the light back to 11 hours/day or so, let it stand that way for a week, then start bringing the light back up. Adding the light won't interfere with the moulting, but it will help to bring them back into lay sooner. The key is to increase the light slowly (if you've allowed the light levels to drop) or to never allow the light levels to drop below 14 hours by paying attention to when the light levels begin to drop in the fall and increasing the artificial light levels as the natural light levels decrease. Of course, that approach requires planning for next year.
You can also force all your hens to moult at once by keeping the light levels steady as described above, then crashing the light levels down by turning all the lights off for a couple of days, then adding light 10-15 minutes every three days until they're back up to 14+ hours. You also have to remember that if you have them under artificial lights and the bulb burns out or you lose power for a day or two they may all be thrown into moult. One of the downsides of adding artificial light.