Your commuter bike, leading the mountain stage

Rule one of this one: the bike does NOT get upgraded. Same commuter frame, same pannier rack, same mudguards — but you're out of the saddle cresting a mountain pass, solo breakaway, switchbacks and a crowd corridor falling away behind you. The pannier bags stay on if you ask, and you should ask. A man passed me on my commute once; consider this my reply, four years late. Tweak: 'keep the pannier bags on' — the only correct choice.