Yes, the overall width / depth / padding of a saddle, the bits that most people check when they are in a shop, are pretty much irrelevant for comfort over a longer distance. The only important thing is support for the sit-bones.
You can get a
very good friend to measure without the use of sand or Blu-Tac, but they need to be a very good friend and I'd suggest avoiding baked beans or fartichokes for a few days beforehand, just to be certain.