Not long resting enough is a problem I had in my first playthrough and I'm not doing much better in my second. I'm amazed at the idea of long resting before rescuing Lai'zel, that's maybe two battles? Maybe some resources spent recruiting other characters?
Either way I'd like to see an improvement on when you need/should long rest. The illithid powers being tired is one hint, but you don't know that until you try and use them. Characters complain, but rarely often enough.