Where/what location (winery or restaurant/farm) does this tour finish at before heading back to Rome? Would it be possible to bring carry on luggage with us (2 people) to end in Tuscany/Siena and not go back to Rome?
We ended the tour at Innocenti vineyards. Regarding staying in Tuscany - I would recommend you ask the tour operator directly about that. It might be fine, or their insurance might require only the same drop off for the same people - I'm not sure what potential regulations they might have to follow.