A shuttle bus runs between Coronado Springs Resort & BB as long as W/S is open. If you're at a theme park, just take the bus to CSR & transfer there to the BB bus. If you're at another resort, you'll first have to get to an open theme park or DTD, then continue via CSR as above.
FYI, during the day, while BB is open, there are buses available to BB from DHS & AK, as well as all resorts. Buses are also available from BB back to DHS, but may or may not be available to AK.
And BTW, you really don't have to walk much from BB to W/S; the 2 are right next to each other and share a parking lot.
Also FYI: CSR & All-Star Sports are each about a mile from BB & W/S. A lighted sidewalk with signalized crosswalks is available.