I and two family members were season ticket holders for over 30 years, but stopped being so 3 years ago, for various reasons. We rarely go nowadays because when we do get the opportunity there are never 3 seats together in the West Stand and rarely 2 together apart from the very front or end rows. Beds is correct, a bigger stadium would increase the number of good seats available for non-season ticket holders and provide the opportunity for all of us to bring along friends, relatives, colleagues and customers when required.
We tried to get an additional season ticket next to our 2 in the West Stand but all were taken except one in front. Almost every game there are up to a dozen seats empty next to us. Does some organisation block book them? Are they kept empty by the club to hand out to people? Always seemed a bit odd.
Its easy to sympathize with you both, but you can get round the situation by ringing the ticket office preferably well before the game which gives the Club better manoeuvrability in resolving any seating problem. It might mean the Club moves you to a nearby location but within ST holders area. Not sure by the way if increasing the Stadium Capacity to accommodate these occasional requests let alone justify it!