A few of mine have been bought without being seen. I still havent been inside them, just driven past afterwards.
My tips:
-Do building and pest inspection to verify that its in 1 piece
-In my case tenants were already living those properties, which verifies that they're habitable.
-Do your own checks via google streetview, pricefinder, residex, etc.
Purchased two unseeen and did exactly the same as the above, except one wasn't tenanted so I fished out a local PM to go through the property for me they now manage the property.