I'm sure others will respond differently...every cat is different, and as you test and get more data, you'll learn how your cat responds.
This is what I did with Max after I figured him out:
If he was 70 or higher, I did nothing.
If he was 60-69, I'd watch. If it was early in his cycle (+3 or 4) and I really needed to sleep, I'd give some LC.
If he was 50-59, I'd give MC if I couldn't stay awake to watch, but I'd get up later and check him. If I felt he was nearing a dose-decrease and I could watch him, I'd let it ride and see where it went. If I couldn't stay home or awake, I'd give him a spoonful of HC.
If he was below 50, he got HC (and I didn't put HC gravy on LC food as many other do, I just gave a spoonful of HC food w/gravy), regardless of where it was in his cycle or my need for sleep.
But that was after I'd figured out how he responded to the lower numbers, and knew that he wasn't hypo at 60 (but the first time he went that low I totally freaked out, and he bounced HARD because I gave him some kibble, and I overfed him so he puked everywhere overnight). Some cats show hypo symptoms at 60, so you really have to watch and observe your cat. It happened a time or two that Max pulled himself out of the 50s all on his own, without any food, and was acting fine all the way down to about 40. He never went lower than that as far as we know. If he had dropped below 40, I probably would have given some Karo or maple syrup to bring him up fast, along with a spoonful of HC or two.