Hi Mike/Carol
It's Ron in Boston. Here are two nominations in NH.
A. Pawtuckaway. This is geographically right between Manchester NH and Portsmouth, NH. 4.5 of 5 stars.
Pawtuckaway State Park is a 5,000-acre preserve in New Hampshire, United States. It is one of the largest state parks in southeastern New Hampshire and is named for Pawtuckaway Lake and the Pawtuckaway Mountains. The park extends from the west shore of the lake to the west side of the mountains. 128 Mountain Rd, Nottingham, NH 03290. (603) 895-3031
B. Tamworth. This is 45 minutes north of Manchester, NH in the White Mtns. Also 4.5 of 5 stars.
White Lake State Park is a 902.7-acre public recreation area in Tamworth, New Hampshire. The state park surrounds 125-acre White Lake, a typical glacial lake. 1632 White Mountain Hwy, Tamworth, NH 03886. (603) 323-7350. This park offers hiking, cycling, a lakeside beach. It is south of North Conway, which offers many scenic local venues such as Echo Lake State Park, Cathedral Ledge, Whitehorse Ledge, Diana's Bath which are worth a day trip.
Suggest calling regarding availability for your particular dates.