dyzzypyxxy said: 
Certainly can't hurt to cut off yellowed or wilted leaves, but I would leave any green ones that look like they could recover. A green leaf is still making food for the rhizomes, so why cut it?
When you dig up a daylily clump to divide and transplant it, you get a huge ball of big, fat rhizomes (well, the size of your fingers, at least) unlike a rose that has all those fine roots.
I would agree that if one can get away with it it is better to leave the green foliage alone, but if the leaves are wilting then the stomata are closed and photosynthesis is reduced/stopped, so they aren't making food. Shortening the leaves to the point where they're no longer wilting will allow the stomata to open and the plant to function more normally. If the root system was able to supply enough water for transpiration then the existing leaves wouldn't be wilting.
I think maybe by rhizomes you're referring to the tuberous roots? There are finer roots as well and they may be damaged in transplanting.
