So she's nice and flat at +3.
Feed normal snack.
Test at +4 (I think I will be asleep by then)
Chnoudi sometimes drops a later in the cycle, but she usually shows her hand by +3.
She will be lower by +4 but not by too much.(I hope)
As long as she's not in the 50s or low 60s I think you could leave her in a room with some food, perhaps give her a teaspoon or two with a drop of honey (to be a bit cautious) let her eat that then leave her a little normal food to snack on. By giving her some extra carbs you might find, if you over do it, that she's a bit high in the morning, but the effect will not be long lasting. It's just about keeping her safe and letting you get some rest.
You do need to pick up her bowl by +10, to make sure she doesn't have a pre breakfast snack, you need to be sure the amps is not good influenced, particularly if for some reason you get a low amps. (another thing the autofeeder is good for, it can hide the food so she cannot eat it)