Fear not! You're a little late but there must be something still available for you.
At the top of the page there is a button "Quick Links." One of the options is "Lake Links" This will bring you to a list of board sponsors by category.
http://www.winnipesaukee.com/links/
These include "Real Estate," "Rentals," "Camping" and "Summer Camps." That last one did include one or two places for families when I looked at it last year. That type of activity may not suit everybody but some folks enjoy it.
Good luck!