I agree with the others about renting an ECV from offsite.
Even if your resort does have the closest stop, it can be a ways form the bus stop to the entrance.
There also is never a particular bus that is closest to the park entrance.
As was already mentioned, the bus stop that is closest at one park might be the farthest away at another park.
In addition to that, Disney also periodically changes the order of the bus stops. So on one trip, CBR might be the closest at MK and the next time you take a trip to WDW, another resort might be closest.
Also, we have been on the bus when it didn't stop at the 'usual' stop for that resort. We took the bus from OKW to Epcot and expected to be at the stop close by where we were left off before. The bus dropped us off at the Epcot stop for a different resort because when he left Epcot, he was going to that resort.