As soon as you can, I'd get a curve to see whether he goes low or whether it's just a very low cycle. We'd dose differently for each. If he goes low, definitely reduce. If it's a long cycle but he's never in dangerous numbers, you could chase the number, go more than 12 hours and dose when he reaches 200 again - if that fits your life.
For today, I'd wait until a 200 and then shoot a tiny bit less - try to eyeball .25
You can shoot smaller doses (.2/.1/.4) if you get U100 needles and use a conversion chart. If your state doesn't require a prescription for needles, you might consider that. It does look like small doses may be in your future. (anti jinx)