For those restaurants that you are considering that do take priority seatings (PS's) I'd suggest making a PS for the ones you really want to try, no matter what time of year you're visiting. The really popular restaurants can be busy any time of year, and you don't want to spend a lot of time waiting to be seated or maybe even being turned away. If you make a PS then decide you don't want to keep it, just call (even the same day) to cancel. In fact, you don't even have to call, I just think it's courteous. PS's really don't commit you to anything, so they won't interfere with your DH's touring style. At the same time, knowing that you have a few PS's will keep you from worrying about where you'll eat or wasting a lot of time waiting to be seated.
Happy planning!