I used my mtb today. I wanted wide bars in case of gusts, and fatter tyres in case of off-roading (there is a stretch where trees often fall in strong winds, necessitating a bit of cross-country) or deep puddles with bumps in them.
A small faff to transfer the bagman to the mtb, and remember to pack a 26" tube, and fit lights, only to find that it would all have been fine on the 700c bike, but I didn't know that when I set off.
Had to remember the wider bars when filtering, other than that, uneventful.
I wonder what the homeward journey has in store? Last I heard, it was going to get arctic this afternoon...