Tarragon is not used to the lower numbers, he is used to the higher ones....that's what feels "normal". Sometimes they don't seem to feel great when they are readjusting to the normal numbers...as he spends more time in the lower range, he will get used to it and feel better. No, I would not decrease the dose so he stays higher! Normal numbers are between 50-120, that's where you want him.....as much as possible. That's the healing range, it allows the pancreas to heal (if possible). Unless you are willing to risk organ damage and give up the chance of remission, I would not try to keep him in the 200s.
They need less food when they are better regulated...that means that they are utilizing the food well, so they don't need as much food. They also have less of an appetite in Spring/Summer than in Fall/Winter. Eating a little less is normal.