I use an Arkel large bar bag with the Ortlieb camera insert. Fits perfectly. My camera is the Fuji XT-1, which is a bit larger than your Panasonic. Prior to this camera I toured for years with the same setup and a Panasonic G3.

No problems with damage so far.

The camera insert fits a DSLR sized camera and one extra lens. If your camera does not use interchangeable lenses or you choose not to bring an extra lens, you can fit a pair of sunglasses, a wallet, a phone, and a couple of energy bars in the extra space, but not much more. I've settled on a short telephoto for touring. I find changing lenses too much of a hassle while bike touring. I've been having great success with this focal length for travel photography.