If you get up at 645, can you shoot then? Or perhaps get up at 630? That way +5 is 1130 which isn't as bad.
The +2 last night, and the night before, was your clue that she was going to keep going down. How much? Well, we never know!
Now looking at the 12th - the entire back half of that cycle was flat. That's unusual. Her pattern seems to be when that happens, you get an overlapping cycles (where you give the AM shot, and it doesn't nadir until after you've given the PM shot).
Now that she's yellow, we'll use tonight as an example -
- if her +2 is still yellow, then you're probably good for the rest of the night. It's never a guarantee, so it's really up to the caregiver what they want to do. Some cats are very predictable, others not so much. I always preferred to get another test an hour before the usual nadir, just in case.
- If her +2 is upper blue, then it's an active cycle and she'll keep going down. To Brons point - lot of wiggle room in upper blues. So I'd feed a little LC, get some sleep and test in 2 hours. Now if she's mid blue or lower, that's a big drop. So LC, test again in an hour.