On the 'can make it a 100+km in a day' I think this is a 'different' challenge.
If one sets out on a ride planning on 100+km and by design or otherwise, stops to eat 'at home' a % through and cracks on then one's ridden 100+km same as stopping and eating 'out' or just cafe coffee and cake. The latter breaks (for me) will nearly always be because I'm riding in company and being sociable. Or taking the opportunity to call in on friends (or even have the friends visit as the ride's raison d’être).
I completed a trip from Weymouth to Exmouth and back (lost car key; don't ask) this autumn but that would've been too far both ways so I cycled 55km to Crewkerne, train (75 mins), 20km in E Devon, returned to train (20km) and then SE from Crewkerne 55km back to Weymouth. Was 'one ride' for me (and was fun!), but might fall foul of
@Sea of vapours' acceptability threshold, I fear. Fortunately it met/surpassed my threshold, which is what mattered.