Forgot to mention, it may very well be skeeter and blackfly season in May. Inland in Maine the blackflies can be really, really bad. If you are camping, be prepared to deal with them.
Some of the smaller lakes in NH used to be very good for smallmouth. Back then, no one fished for them. The smallies were very dumb and aggressive.
When I was in high school my folks rented a cabin on a small lake in NH and we caught some great smallmouth. I wish I could remember the name of that lake, but it was in the Lake Wentworth area. I don't know that there is much creek wade fishing for smallies in NH or Vermont, the smaller streams are typically trout deals.