I agree with the others. It would take you forever (and a lot of extra miles) to do what you were thinking.
I checked a WDW transportation map that I picked up last March. The Dolphin and Swan are listed on it, so their buses would drop you off right at the entrance to WDW.
In case you have never ridden a WDW bus with a wheelchair before, here are some "bus pointers".
1) The bus drivers do load guests in wheelchairs or
ecvs first (because it is easiest to do when the bus is more empty and the other guests don't get in the way). If the bus is already standing room only when they pull in to your stop, they may have to turn you down for a ride because there will not be enough room inside the bus to manouver the wheelchair on.
2) The ramp or lift is located at the back door of the bus. Don't get in the line with everyone else who is waiting for the bus. Park the wheelchair or
ecv out in the open (but stay on the sidewalk) about where the back door of the bus will be when it stops. That gives the bus driver a chance to see you.
3) When a bus comes, be ready to attract attention to yourself. Stay on the sidewalk, but wave your arms, give exaggerated head nods, etc. to catch the driver's attention and let the driver know that you want to board.
4) When the bus arrives at a stop the driver will usually look toward you. If it is not the one you want, shake your head so that the driver knows you don't want that bus.
5) Several seats in the back of the bus are convertable (across from the back door). They can be used for seating, but are folded up to make room for a wheelchair when necessary. If someone is sitting in them, the driver will ask them to move when a wheelchair needs the space. There is a sign above those seats to advise people that they may need to move.
6) After loading, a wheelchair or ecv is tied down on the bus with adjustable straps. It can't be just parked on the bus and the driver will not be able to let you carry the person and their wheelchair on.
7) Someone in your party should know where safe tiedown places on the wheelchair would be. A safe
tiedown point is part of the frame of the chair; things like swing-away footrests or antitip bars are not parts of the frame, so they would not be safe tiedowns. The drivers can guess (and is probably quite familiar with rental wheelchairs or ecvs), but wheelchairs differ in design, so it's best to know. We mark some safe tiedown points on DD's wheelchair with bright pink tape. It's much easier to tell the driver to look for the tape than to say "that upright pipe to your right is OK." We've had many drivers say that it makes the loading process much faster and they wish everyone would do that.
8) If they are not able to board you, the driver should offer to call dispatch and have a wheelchair accessible bus sent. If they don't, be prepared to ask if they would let dispatch know that you are waiting and need to be boarded.
Have fun.