My Neko is also on Levemir, and she often isn't consistent about when her nadir lands. Sometimes it's earlier, sometimes it's later. I wouldn't consider 88 a dangerously low number. I would observe by testing hourly, but not intervene with high carb food until Juno gets closer to 50, unless you need to get to sleep. You could try feeding some low or medium carb food now to try to encourage him to surf in the 80's. Those are nice healing numbers.
The one thing that's difficult about using Levemir is that often you will be faced with a lower number at preshot. Neko often nadirs at or near preshot, but I know I've got over 4 hours until onset and I'll be feeding so I know she'll keep on rising. I noticed you've missed a number of shots when the preshot is lowish. If you are going to be home and you see a low preshot, have high carb food and plenty of strips, it's an opportunity to see how Juno will do. Neko has had a few cycles where she started in the 80's and varied by no more than 10 points the entire cycle.