We are going to Ireland and possibly dip into Scotland/Wales from Sept. 8-Oct. 5. We have a cottage in County Cork for the first week. I'd love to just travel after that without hotel or Airbnb reservations, or making them as we go, depending how much we like a particular locale. Would that be a mistake?
No. We frequently do it. You may want to make reservations a day or two in advance but the internet makes that easy.
I think it really depends on whether you really care where you stay and how much time you will spend looking
Personally, I hate wasting time going from one hotel to the other looking for availability and not knowing what it is going to cost me so I always pre-book.
I make reservations that can be cancelled without penalty. Then, I keep track of cancellation dates so I'm not penalized for cancelling. In your situation, I would probably wait until a few days into that first week before deciding my next move. I used to travel without reservations then either just show up or call a day or two in advance. It worked well.
Depends on the number in yr party, we were 6 folk needing 3 rooms, and found that difficult, should have prebooked. Also, beware that sept 30 is end of season for a lot of attractions s, and they go to greatly reduced hrs & days at that point
As you can tell from the different responses, it's really what you are comfortable with. For my wife and I, other than the first and last nights, we seldom have reservations. That allows the freedom to change your itinerary at the last minute in the event you want to stay someplace longer or shorter, or go in a completely different direction. For trips with a pretty firm itinerary, making advance reservations makes sense.