Where to go Tuscany for 3–4 weeks if you want countryside but still need groceries/train access?

I’m looking at spending 3–4 weeks in Tuscany for a slow, relaxing holiday (haven't picked a time yet but probably at the end of this month) and I’m trying to choose the right place before I start seriously looking at accommodation. What I’d ideally like is somewhere that feels rural,quiet and scenic, but not so isolated that every grocery run or day trip requires a long drive. I’d love to have a supermarket, a few cafés/restaurants, and ideally some kind of train connection within reasonable reach, if I decide to do some sightseeing.

There's a few different areas I've found that seem to be ideal like around Lucca, so I can get to Pisa/Florence, or area around Arezzo, seems practical for trains and day trips. Besides, around Siena, although I’m not sure how convenient it is without driving everywhere.

Val d’Orcia, which looks incredible, but I’m wondering if it would feel too isolated for a longer stay.

I’m open to renting a car for at least part of the trip, if public transport doesn't work out but I’d rather avoid the hastle.

Has anyone here stayed in those areas and can tell me if that would work out for what I've planned? Where would you recommend?