It really varies, how long it takes a hen to go back to laying after a molt. Breed plays a large part, of course, but I know that inside of my flock there is still a lot of difference inside of the the breeds. I don't know about your dorking, but in theory, all of your other breeds are relatively quick molters. The light will hasten the completion of the molt also, something that I actually try to avoid doing; I prefer to let my flock molt naturally, waiting to turn on the lights until nearly everyone has finished molting. You have the light on, though, so I would think that changing that again would just confuse their bodies further. Someone suggested you increase the protein intake as they try to finish their molt, and I very much agree with that advice. Molting is hard work, it takes a lot of protein, and you want them to go ahead and invest in nice, healthy feathers that will serve them well through the winter months. High quality cat food is often used as a high protein TREAT (don't over do it) to give to hens coming through their molt. I like to just go ahead and buy a little bit higher protein feed and introduce it to their current feed, slowly replacing it. When everyone is finished molting, if their weight and overall health seems to be where it should be, then I slowly re-introduce the regular layers rations (I use 16% layers, but again, it depends on your flocks needs) and stick with that. I have found that towards the end of unusually long winters my flock will need a higher protein feed introduced again for a while. Last year, when spring refused to arrive, I also added alfalfa to their diet and the combo really seemed to do them a great deal of good.
congratulations on the eggs!! I am always amazed at what a little tiny chicken is able to produce for us in the midst of these miserable winter days!! Good girls.