Gotta pre-plan a bit. I like to travel light so I won't bring my pannier bags unless I know I might use it. I've been caught in situations before where I've wanted to pick up some takeout on the way home, but those wouldn't have fit well inside my pannier bags, anyway. Consider getting a front pizza rack or cargo box if you carry stuff often. I personally would hate riding such a bulky bike unless I'm hauling stuff but I have a buddy who has a cargo box up front on one bike and always rides with double pannier bags on the back of another bike. I think it's overkill but he likes to be prepared (packs different layers, gloves, hoodies, etc in the panniers). I don't even do casual rides with him anymore when he's on those slow bikes. I pack what I need and go as light as possible. It makes me less prepared for the unexpected but come on we're just cruising around town, not bikepacking.