I probably would have given the full dose if you are home to monitor. 153 is not much different than 195. You can give Prozinc up to an hour late, but if you do, adjust your next few shot times to gradually get it back on schedule.
Updating to add... At least with Mia, I find that it is best to keep consistent dosing to the extent possible, so I try not to change up dosing based on each pre-shot. (I'm not saying I do not reduce when it is dangerously low, but I try not to 'get scared' just because it is a little lower than normal and change my dose.) Also, keep in mind that Jester got to 85 which is not too low at all, especially with a human meter. And, as I mentioned before, 153 is not much different than 195.
A lot of this is up to you and your comfort level. I am finding that I have to take on some risk to get the results I want, BUT I would not be doing that if I was not going to be able to monitor. So, take how much you can monitor (and what carbs you have on hand that you can manage to get down him) into consideration when deciding what to do at times like this.