1 day would be incredibly satisfying to do. If I did that, I’d want to start early, about 7am so I finish in daylight. If I did 2 days, I’d start early afternoon so stop/sleep when it starts to get dark. Not keen on carrying loads of heavy locks so can’t really go inside anywhere for food anyway. That’s why If I do plan to stop, wild camping is the only option.

Sorry, meant just a bivvy or bivvy plus sleeping bag etc?

Forgot to add the bike would be either a 130mm full sus or rigid XC bike. I’ll probably choose the full sus for comfort and less fatigue.

I’ve done it in a day once and done it over a couple of days several times with a cheeky bivvy.  

Just a Bivvy? Or a tent/shelter too?