You may want to looking into something like the Nikon, J5. With the 10mm prime it is a 27mm mounting to a camera body, quite similar size to a pack of smokes.
I saw one go for $222 last evening and it included the 10-30 pd zoom and the 10mm prime. Underrated, discontinued, defunct system. The one inch sensor is used in a lot of high end, more expensive point & shoot cams by canon and sony.
A full J5 kit, with FL equivalent to 18mm to 300mm fits easily in a fanny pack.