Loire Valley unique places to stay

We enjoyed staying in Chateau de Pray. It is about 5 minutes by car from Amboise. There are a lot of little towns to visit. Azay-le-rideau is quite lovely and the chateau is pretty. You might determine which chateaus you'd like to visit and go from there. My favorite chateaus were Clos Luce (Amboise, Da VInci's), Chenonceau, Villandry (both have amazing gardens) and Chateau de Chaumont. Chambord is immense and interesting on the outside. Chinon is a nice little town, and a good wine area. We enjoyed the wines and area of Vouvray as well.

Another fun option could be to stay in a troglodyte B & B. There are several areas where you can find these cave dwellings, including Saumur and Turquant. Right next to Turquant is Montsoreau, which is often on lists of the most beautiful villages in France, and it's also near the Fontevraud Abbey - really a gorgeous area in general!

Here are some examples of what troglodyte rooms often look like: https://www.anjou-tourisme.com/fr/preparer-son-sejour/ou-dormir/gites-et-locations/vivez-lexperience-dun-gite-troglodytique

Seven years ago, we stayed at Château de Marçay, 37500 Marçay - Chinon in July. Our room was huge, with a totally renovated huge bathroom. All the rooms seemed different, and it was definitely a historic-building experience. I should note that there was no air conditioning, and we ordered a fan from the front desk to put in one of our multiple windows in the evening. (We bought our own fan in the next stop, in Dinard.) They had an excellent restaurant, but I wouldn't want to eat in the same place for five nights, anywhere. I do mean to say that the "chateau stay" (with a kitchen garden, AFAIR) was very attractive, but not quite at the five-star level, if that's what you're looking for. I'm not whining, but our otherwise gracious and attractive breakfast was affected by a large bicycle tour group that was put in a private dining room. Quiet night in our room, however.

We made a conscious choice to stay West of Tours. I personally would not stay five nights in the same spot in the Loire, but that is a matter of taste. You may also prefer to stay East of Tours for the most famous Chateaux. We were West for Azay, Villandry, and Fontevraud Abbey - and our next stop was the coast, for Mont St. Michel, Dinan, and so on. Your OP does not say that you have a car, but I assume that from "five nights." I thought Chinon was an attractive place to walk around and find a dinner. Maybe you would find fewer dining places "fully committed" in September!

Edit: I can't review the restaurants or hotel, but I agree with the next post that Azay is a lovely place to make a non-rural stay. I suppose it could be crowded on nights they have Son et Lumiere or something at the Chateau. I believe Azay is smaller and wealthier than Chinon.

I'm not sure if it's unique enough for you, but we totally loved Hotel Biencourt in Azay-le-Rideau. It's in a building that used to be a girls' school in the early 19th century, and there are wall paintings with the names of the teachers. The innkeepers are the nicest, most helpful people you'd ever want to meet. The village is small, but it has a handful of very high-end restaurants as well as more casual places to eat. We enjoyed the Saturday morning market in the village square; we bought some beer made in the region and some amazing radishes, along with (of course) cheese, bread, etc.

While in-town hotels may have good restaurants attached, an official "half-board" plan seems most common at locations that are more isolated, of which I do think you'll find a few around the Loire Valley if you search "castle hotels."

In order to charge a fixed price it will often be a set meal or limited-option menu, such as this one near Amboise: http://www.chateaudeperreux.fr/en/meals.php. This 2-star hotel on the train-station-side of the river in Amboise also has a nice restaurant: http://en.labreche-amboise.com/243-tarifs. Both listed in Rick's France book.