Seekonk is a great option as it is very central. You can do exit 1 if you would like otherwise, as you know exit 2 will put you right on rt 136 in Swansea.

If you decide to go down 136 to newport through warren, bristol, and then over the mount hope bridge into Portsmouth i will meet you at some point along the way. I live about 4 miles from the mt. hope bridge and thats the way i go to Newport everytime. Once we get into Portsmouth, we could take east main road as it is pretty scenic passing by the vinyards.