I just got an fstop Bandon today - a messenger bag similar to a Domke
https://shop.fstopgear.com/us/products/millar/bandon.html
I really like it, and surprised how much it fits. Fits my 300mm, as well as all my lenses and a body, and my ipad. I have to figure out how to carry my lenses without having them in bag, but that is for later.
These Millar bags are 50% off through 4/18 - so about $55 shipped for this one. Fstop bags in general appears to get excellent reviews.
I am not affiliated with fstop, btw...