If you use your camera enough, sooner or later you end up with a closet full of camera bags. The key is you want to be able to travel with just the right amount of equipment for the job, and different bags have different jobs.
We bought a Think Tank Mirrorless Mover 25 back when we started with the EOS M3. It's a great bag, and we've filled it up with the EOS M3, the 22mm prime, the 11-22 wide angle zoom, the EF-S 55-250 zoom (with adapter), a small flash, spare batteries and lens cleaning accessories. But there are days when I'm carrying 2 kids up (or down) a mountain and it's just a bit much. On those days, I'd just hang the 11-22 zoom on my shoulder, but of course, it would dig into my chest or get hammered by the kids.
BestBuy had a sale on the Mirrorless Mover 10, and I ordered it to see how it would work. The good news is that it fit nicely on the Deuter Kid Comfort III's waist belt, even with it cinched tight. It has sufficient capacity for either just the EOS M3 with the 11-22 zoom + the small flash, or the EOS M3 with the 22mm prime and the 40mm (with adapter), a spare battery, and lens cleaning kit. On the side there's enough room for a mini tripod. Together the entire kit would weigh 1kg (2.2 pounds)
The bag comes with a shoulder strap, but in practice I'll probably never use it, and would detach it before traveling. The idea is that on a car based touring/hiking trip, you would have the full kit in the car. If you drive to a trailhead and then have to carry 2 kids up a steep hill, you'd move what you need into the Mirrorless Mover 10 and then you'll have a lighter weight kit that would leave you hands free (for kid carrying) when you're going up and down a mountain. Or you could carry a spare body and lens while your wife carried the main camera.
When BestBuy shipped me the camera bag, it didn't have a strap. I called ThinkTank, and they didn't even ask for a receipt: they just immediately shipped me a camera strap. Whatever else you may think of the company, they have fantastic customer service.