Thanks for pointing me in the right direction. I've found the singles offers which says you must travel on the train you book, but am wondering if the super off peak returns might be better IF they offer ANY train, in case I miss the one I booked. The info bit on GWR isn't clear to me. Don't worry if you're not sure, I can check at my local station. Just realised I've not yet checked the split train tickets, but maybe that's the same restriction, I'll find out.
I feel ok about meeting new people, cos in a sense you're not are you? I think a day will be enough for me just for now. I hope that I WILL be kicking myself for not having planned to come for longer. But it will be only 6 months since Goerge passed away and my first full day out.