I have difficult time imagining people in a 45-foot bus needing that much battery capacity. It seems a mismatch.
Best use of lithium technology is probably for those boondocking on a regular basis, and I expect owners of 45-ft rigs to normally stay in luxury resorts. I may be completely wrong though.
I guess you can visit National Parks, boondock at football games, etc. with a 45-ft motorhome, although I expect the demand for this type of motorhome isn’t that great. And even if it had lithium batteries for convenience, why so much?