My first thought before I read through this was the 24-70 zoom but after I read through it I also fall into the 40mm pancake camp. I also LOVE to shoot my 15mm EF Fisheye.
However, what about another thought... go old school. Throw on whatever lens you like, fast prime, whatever. Then go all manual. Get the exposure close and then get out the gaffer tape for once you fine tune a good focus point for the distance. Find a focus point that is in the ballpark and then shoot away. This way, the focus will be good in many shots and AF performance won't be an issue.
Hey, I'm not saying this is the way to go for EVERY shot but you might surprise yourself with what you can achieve. The film is cheap and all it takes is getting a few great shots each session. Even if the focus is off a tiny bit, it will still be a great shot depending on the aperture, light and composition. Piece of cake!

(LOL)
Also, if you get WAY BACK with a 70-200 f/2.8 IS, you can take advantage of the longer focal length to get fairly focused shots from a distance at f/2.8. (With decent shutter speed.)
Another idea: Set up some kind of picture trap. You know, set up the camera however you like pointed at some kind of irresistible attraction and fire the shutter remotely (on Silent Shutter mode). You can get those radio remote shutter releases online for pretty cheap. I've had one for years. Or just use the good ole wired one.
Good luck. My main point here is to have fun and see how many things you can try to see what works. Let us know how it goes and share some shots.