I was looking for something similar myself. Something I can throw a moleskin, a kindle, a wind shirt, lunch and a bottle of water into. the other main use I've got is as a dad bag (nappies, wipes, drink, snacks, coat, change of cloths). I'd prefer a bag with a top grab handle and a tall side stash pocket for a water bottle.
I'm looking for a small everyday rucksack for three main (pretty lightweight) uses and given that you are all out an about quite a bit, I wondered if you have any recommendations? This may be more than one bag. I'd prefer a rucksack over a messenger bag and smaller rather than fully featured.
I'm also 6ft2in, 46inch barrel chest and a long back (and yes that does mean stumpy legs).
Uses is order of frequency --------------------------
A) Day to day commute (bus, train, walk) bag to carry a Kindle, moleskin, pen, soup, fruit, wind shirt, gloves, torch - we have no street lights in the village or by the river. I don't need to carry a laptop or A4 folders, I have a big formal bag for client visits etc.
B) Dad bag (A couple of nappies, drink, wipes, change of toddler clothes [they are small], toddler coat, snacks, bear [well a small giraffe], post-its, pen, chalk, wind shirt for me). Basically a small bag I can take with me everywhere when I'm out and about with my toddler daughter.
C) Basic small daysack for walks / beginning trail running (wind shirt, keys, hydration bladder, snacks, torch, phone, and when cold - hat, buff, gloves).