Really LONG second day
Sandwich, MA to Providence, RI is a LONG way for a day sail. I went from Sandwich to South Dartmouth, MA in about 3.5 h at 6-6.5 kts. South Dartmouth is about 30% of the way there, so you may be looking at 12h + easily at 6kts.
Anyway you can get through the Canal the day before and layup in Onset or Marion?
If you liked my advice/response, give me some rep points. If you didn't......well what do you expect, it was free.