Since I don't know how much nutes the plants have already got, it is hard to say. I would say to hold off for more than two weeks if I actually though nutes was the only problem. It might be part of the problem, but I don't think it is the whole problem. In fact since your soil looks dry - it is very possible that nutes have nothing to do with it. If you make the cuts and the plant grows a few inches over the next week and looks completely healthy, you can consider giving it more nutes. Go light though - it sounds like you are new to this, and it is better to err on the side of caution.
Snce you are confirming that the top of the soil actually is dry - if this has been pretty normal, then I really think the problem is the clone was just not well cut before the grow started. Cutting off the extra bits will get the plant to a good size so you can be sure the root system is able to support a healthy plant. The lower branch is actually large enough to turn into its own clone, so you could potentially turn it into two plants if you didn't want the branch to go to waste.