I might get a new tote for air travel for my trip, vs. Use something I have.
For your " extra" bag in the plane, do you try to maximize size, to serve as almost- luggage, or use sizes you'd carry anywhere? Or insist on water bottle pockets and open side pockets? Top zip seems a must. Wide shoulder strap vs tote handles? Special bags that are made to slide on carrying handle? Lightweight nylon vs more structured? Also I don't think this would be my " day bag" because I do think that should be smaller & maybe waterproof nylon , lightweight. Add any comments you'd likd about day bags. I'm torn between sizing up for the mantras of " just stuff your jacket in your bag" approach vs fear of looking/ feeling like a pack mule so would stick with a medium sized bag just for usual items and maybe room to stuff a scarf or hat in.