It's next door to my house which is 30kms south of Monterrey. It is a time share and used to have a KOA campground. The campground is still there next to the water, with 15 amp service. Your fiver will fit beautifully.
There are lots of things to do here as well as in Monterrey. Monterrey has a very nice riverwalk with boat rides similar but nicer than San Antonio, Tx.
Chipinque is one of many national parks and is located in the city of Monterrey. The views and hiking are spectacular but there is no camping other than tens allowed.
In Santiago (Bahia Escondida), there are mountains, waterfalls, hiking, boating, and many ecotourist activities.
Unfortunately, we won't be home this summer as we are head to a trip around the western U.S. and across Canada for five months.