You don’t have to plan from scratch. These rides pass close to Crescent Bay, mapped and written up by route publishers around BC. The full maps and turn-by-turns live on their sites.
The BC Trail— BIKEPACKING.com · 1,164 km route, passing within a kilometre
Loop Kaslo Slocan— Trails BC · 221 km route, passing within a kilometre
Getting there with a bike: province-wide buses, ferries, and shuttles are listed under Transport (some serving Crescent Bay may be listed there rather than here).