Do you have a double stroller? If so, why not bring yours from home?
I bused it this last trip two weeks ago. First time with two kids, we didn't enjoy it since we're used to the Deluxe resorts and we really wanted to get away for Thanksgiving so we took the moderate resort since all the deluxe resorts were sold out (and regretted it). But that's just us.
It's totally doable and I wouldn't hassle with a rental car then you have the additional hassle of parking and trams. The bus is much more convenient.
You need to plan ahead and it can work. Here's what I did:
I had the diaper bag (which next trip I'm not using, I'm going to put the diapers and wipes in a Skip Hop Pronto - we'll be done with bottles
We had a totes foldable tote bag that I used to consolidate all our stuff at the bus stop. Stuff that we kept throwing in the stroller basket: lightweight blanket, sippys, snacks, jackets, etc...
I also had a baby bjorn that I put in the tote bag.
DH would always grab and fold the stroller and take one bag. I would take one bag and the baby. My 4 yr old jumped on the bus himself.
On the bus, we always ran towards the same seats if they were available. We put the stroller and the two bags under the seat.
We always made sure we were folded and packed away before the bus arrived. You can't be doing this while the bus is at the bus stop. You really have to be ready.
After a few bus rides, we had a system that worked so well that once I was able to do it by myself. DH had to go handle some business that couldn't wait. So he left us in AK. I was able to put the baby in the bjorn, get the bags and stroller on the bus without any additional help. I met him in DTD with no problems.
The only downside we found to the bus was when the baby was asleep. We wished we could have left him sleeping in the stroller.
Hope that helps,
Mare