There were 6 of us -- my husband, my parents (in their 60s), our 2 and 3 year old, and myself. This met our needs perfectly.
An amazing amount of movies, books, games, and toys for the kids. There were even plates, utensils, and cups for the kids (including sippy cups). We did block the stairs at night because we didn't trust the kids going up and down by themselves at their age (older kids would need to be careful, but should be fine). The kids LOVED the outdoor playhouse.
The WiFi worked great, as well as the hot tub. We did not use the grill or the fireplace.
I agree with the other reviews that the only thing you need to pack are clothes and groceries. The only thing that was not provided that we happened to being was paper towels. You may want to bring extra toilet paper just in case.