All the BBF16s I have owned, and other sources, have given the address of the Grange depot as Kents Bank Road. However as Kents Bank Road and Albert Road are adjacent I'm sure the depot never actually moved. Depots could easily change their address without moving - witness Burnley depot moving from Grimshaw Street to Centenary Way, and Blackburn George Street moving to Manner Sutton Street.
Grange was always listed as a full depot, implying that it was head of a 'District' with a 'District Traffic Superintendent' (later District Superintendent) in charge. However, it's likely that these definitions weren't always rigidly applied.
These depots without a permanent allocation (in the case of Grange, of service buses) often had an unofficial one. I remember, in my bus-spotting days, that the last Ribble Olympic I 'needed' (and for a long time) was 251 (DRN115), which was officially allocated to Kendal. On one occasion when myself and a school friend were visiting Kendal (which we did at least once a year) I asked a driver if he knew where we might find 251. We received the response that that particular vehicle 'was often at Grange'. Years later, when working for Ribble myself, I discovered that Ingleton depot had its own unofficial allocation. The two service buses were 36' Leopards 469 and 562. The third vehicle was scheduled to be a DP, but I don't know which one was nominated as the regular Ingleton one - Lancaster's allocation at the time was 826/8/9.