We keep running into this issue. Some night it would be good to get a nadir overnight. That will tell us if he dips low and is slowly coming back up by amps or if he has a cycle that just slowly goes down and the amps is the lowest number of the cycle.
You have choices but all are a little nerve wracking. One, you have to make sure the amps is a rising number so that means 20 minutes without food and a retest. Then if he was up in the 180s for example, you could shoot a reduced dose (assuming you would be around to monitor.). That isn't an option today because you fed him. . Two, feed and wait at least 1.5 hours and then test and shoot a reduced dose. (reduced because you have to consider his number is partially food influenced). That throws your schedule off by 1.5 hours. Three, wait 2 hours and shoot a regular dose. This has the potential for wrecking up your schedule but the way he has been having long cycles, it might be that the pmps would be too low to shoot and you would skip and could get back on your regular schedule in the am.
All are less than ideal, but you are doing the right stuff. He is just throwing lower numbers than we expect. Your one unit was the right dose last night. He seems to be requiring less insulin each cycle or two. This is a good sign but makes dosing tricky.
Does any of this make sense?