grandmajosey can I just check as you live in a ground floor flat if you are ok with stairs? It seems your grandson has access to the stairs in his home, just wondered it you are ok with trotting up and down with him.
To answer your questions, I don’t think you’re unreasonable to want to have your grandson in your home, there is something special about it. We used to mind one of ours when his Mum went back to work, usually a day a week, took him to places accessible from there. It has always been in their home, about an hour away, until very recently and he’s 7 now. It hasn’t stopped us having an excellent relationship which endures. Perhaps be patient a while longer, the time will come I’m sure.