Nameless Why focus on non park and ride spaces ? Park and ride seems a reasonable option when there simply isn't land on which people can park and walk. The key will be making the ride bit efficient so the time it takes to get back to your car by bus isn't significantly longer than the time it took to walk to Worton Grange.
I used to park at the Holiday Inn, and I find I get back to Mereoak on the bus a bit earlier than I used to get to the Holiday Inn. The bus lane through the middle of J11 cuts out a lot of traffic.
The "family" ticket also seems to be a group ticket, so two people (maybe more) can get a return for £5.
Neither P&R is really convenient though for people coming from north of the stadium, i.e. anyone who lives in Reading, which is a slight flaw, some might say.