I agree with the previous posters. Taxis get very expensive / very fast. The ability to stop at the grocery store to pick up supplies / groceries easily (a big advantage you can have in a condo for a breakfasts in, lunches in or sandwiches you bring to the park, and snacks in -- all options that save a great deal on meals) isn't all that easy to do without easy transportation to a grocery store too. Three stops at the grocery store during a week in Orlando is probably the norm for me.
I've only stayed offsite without a car once, and this was a mini three night / two day stay. When we arrived, my cousin who lives in Tampa picked me up from the airport. He stayed with us two our our three nights. We stayed at a hotel walking distance to SeaWorld, so walked there and back for our first theme park day. Day 2 we went to Disney's Animal Kingdom, and my cousin gave us a ride over there on his way back to Tampa. We took a cab back to our hotel after our AKL day and with tip it was somewhere around $40. We spent the evening at SeaWorld walking there and back again. And the next day we took a cab to the airport. That with tip was somewhere around $45.
Here is a link where you can calculate your own fares for the trips you plan.
http://www.taxifarefinder.com/main.php?city=Orlando.
Taxi's are quite expensive and if it weren't for my cousin and being walking distance to SeaWorld I would have rented a car even on this short trip. (I should mention that our hotel had a shuttle to the Disney Transportation center that we could have taken. There were limited times, however, and after going to ALK we wanted to have a quick dinner (room service at our hotel) and catch the last Shamu Rocks show at SeaWorld again on our very short mini trip) // Saving $40 wasn't worth missing that, which would have been the case for us taking the shuttle. // Note that after our day at ALK there were lots of taxis out there including vans that would have been big enought for your group.
I absolutely love offsite condos and house options, especially for longer trips, but would not consider these without a car. (Just me)
Many of the folks from the UK take the Lynx bus to the parks, but then to make this feasible they usually stay somewhere on I drive very close to bus pick up points. Trasportation times and bus transfers described on posts I've seen didn't seem all that convienent and wouldn't be my choice, though. I think many of them were just so used to public transportation back home and didn't think a thing of it plus didn't want to attempt a car that drives on the other side of the road than what they are used to. (If you want to hear about taking the bus from experts, go the the tripadvisor forum for Orlando. Have seen some big Lynx bus experts who post there regularly.)
