"Of course I don't doubt that there are many other such places, but how does one go about finding them other than trial and error?"

Like Willie sez, we too tend to avoid eating at Hotels. All faded decor, guests and food alike.. Yuck! I've often walked straight out the door after walking into an hotel for lunch. They're too often lacking in any charm or appeal other than the possible surrounding scenery.

Go for an historic coaching Inn which has guest rooms instead. Not all of them still offer lodgings, but you can check out online in the area you're traveling to for those Inns which do. All the charm of an historic building (oak beams, creaky floorboards and ghost stories galore), much more genial 'traditional English pub' type atmosphere, and the food is likely to be much better too, IMO!