Right I’m going to do something like this next week (thank you for your suggestions though)
Train out of Manchester to Shrewsbury or somewhere like that (dead cheap/won’t require pre-booking and won’t take long). Then head through the Wye Valley to the Mendips to see a friend and her baby and stay with them at the commune-type place they’re living at the moment (in an old burger van!)
Then to Bristol to see a pal who left Manchester last year, before heading around the Welsh coast to Pembrokeshire & The Gower, before heading back to Aberystwyth to get the train home - or continue up to Bangor if I have time/the weather is not too bad.
Should be about 850km to Aber or 1000km to Bangor. I have a little over two weeks off work so totally doable either way, including a couple of nights with my friends.
Route looks something like this: