I used top think 5 nights was good but with a seven year old and no other adult around I am thinking at least 7-8 nights may be ideal.

I am amazed by those who stay up to 30 days! What do you do for that whole time? Do you eat in the villa for most of the stay?
I spend most of the extended trips solo, as DH doesn't have lots of time off, but he does fly down for a short trip. I either walk to Gooding's (from DTD) or order from Garden Grocer. I do have some restaurants I must visit -like the Coral Reef or GF Tea - but I do eat about half of my meals in my room. I get food to go, also.