For me, I'd choose the two rooms at POFQ for a number of reasons, but the main one is that renting DVC points is a risky proposition. I mean no offense to DVC owners here who rent their points.
What I mean is that if you rent points, you are basically stuck with the reservation. You'd have to reserve months in advance and if your plans changed--or your daughter's or son-in-law's plans changed--it's unlikely you'd be able to change the reservation. And more unlikely still that you'd be able to get a refund.
When you reserve a room through the WDW reservation system, you can modify or cancel your reservation if needed. Not a problem.
I've stayed at both resorts and I like them both, however, I prefer POFQ. They have a much better variety of food at their QS, there's usually only one bus stop, although late in the morning once on my last trip there, they also picked up at POR, but only after picking up at POFQ, and I love the boat to DS.
SSR has multiple bus stops and it can seem endless when going to MK, for example. This wouldn't be an issue if you're driving, but maybe you won't have a car.
Both resorts have beautiful grounds and a lot of walking paths . . . assuming you still want to walk after putting in 10 miles in the parks!
One other vote for POFQ: If your daughter and SIL decide not to go on this trip and you still want to go, you could just cancel one room and keep the room you booked for yourself. But if you have SSR booked, you are stuck with the 2-bedroom and in fact stuck with the entire reservation.