Hello Matt.
The weather should be reasonably good in central BC in the fall. There will be some poor days, but the weather is quite stable there.
Accommodation may be another thing. Do your homework on that, hopefully Air-Hart can make suggestions for you. B.C. is never low cost anyway, but the fires this past summer have made it more difficult for local residents, so what might have been tourist accommodations may be being used by local people. Make sure you have accommodation established before you go.