We have 4 young kids and we have gone with both Grandmas. So trips with 6 or 8 people. We have stayed on site and off.
If your focus is Disney Parks then stay on site. Good Options would be:
The Cabins at Ft Wilderness that fit 6 people. You will want to rent a golf cart to get around. They do not allow cars to drive thru the area. They have internal buses to take you to the pool etc but we found the Golf Cart was so much easier. It is considered a moderate resort and they have a waterslide at the pool & a really nice kiddie pool with slides. In addition to a bus to the Magic Kingdom you can also take a boat.
Art of Animation fit 6 also. It is considered a Value Resort but it has a really nice pool and spray area for toddlers. Lots of things to walk around and see. Very easy to have your meals just walking to the food court unlike Ft Wilderness.
If you are only doing a day or two at disney than maybe offsite is for you.
We LOVED our offsite vacation. We stayed at Reagal Palms in a 4 bedroom townhouse with 8 people and it was so roomy! Full kitchen, washer dryer, next door to a grocery store and many restaurants, they have their own restaurant at the pool. The pool was FANTASTIC! Lazy river, water slide, zero entry for little kids. It is abput 20 mins or so from orlando (Davenport area) but it was so cheap. Around $700 for the week. We did Sea World, Nick Resort, Aquatica water Park and some smaller stuff this last trip. I thought about doing a disney character meal
at one of the resorts (since we weren't buying Disney Park tickets) but we just ran out of time. It was the least expensive trip by far and so far the best trip we have had. I don't have pics of the Townhouse on here but here are some pics of the pool and our time in orlando. We rented the Regal Palms place thru VRBO and picked a place very close to the pool so we could walk back and forth easily. I did all the planning for all 3 trips and this one went the most smooth. The least waiting in lines, not dealing with crowds. My husband and both grandmas want to do this trip again rather than the onsite one.
HERE ARE MY PICS FROM REGAL PALMS AND NICK RESORT:
https://www.facebook.com/media/set/?set=a.10202010335327408.1073741833.1456650682&type=1&l=a3b51a3835
Feel free to PM me if you have any questions. I got an AWESOME deal on the Nick Resort with Seaworld and Aquatica tickets (I think they were 14 day tickets) We did 1 night at the nick with 2 suites for the 8 of us and it came with those tickets for 14 days at Sea World and Aquatica (Kids were all FREE for those tickets). I think it was around $700 for all that! It was a CRAZY deal!
Okay I just looked it up:
The price we paid for 2 adults and 2 kids to have 14 day passes to both Aquatica and Seaworld plus 1 night at the Nick Resort in a 2-Bedroom Suite was $370.92. THan we just doubled it and booked it again since we had 2 more adults and 2 more kids.
So at this point we had a fantastic place to stay with an amazing pool, 14 days of Sea World and Aquatica water park, The Nick Resort to see the live shows and meet the characters and play in the really cool pool/water park. And for 8 people we were at $1500!!!! No way could I have done that if we stayed onsite.