I’d go with the biggest size Timbuk2 messenger I could find. I’m so glad I got my hands on a classic messenger in xl before they discontinued it. I used one when I worked as a messenger. Loved it so much it kicked off an enormous timbuk2 messenger bag collection. Got like fifteen of them. But never did get an xl. Was just so big lol.
When I heard they were discontinuing that size, I went on their website and found they were selling the remainder off dirt cheap. It’s now my go-to bag for any trip, with or without bike.