I did it twice this year, once in early April and once in late September. It was great fun both times. The first was with an unfit friend and the second with a large group of mixed abilities, so we went in three days, split with overnight stays at Malham and York, and it was very steady.
Very doable in two days for anyone of moderate fitness. I’m hoping to do it in one day next year but it’ll be going some. I think someone has already done it in about 16 hours.
I’d advise 25c tyres at least, it’s pretty broken up in places. As others have said, the drop into Pateley Bridge is quite character building, especially if loaded with panniers…
I have the gpx files if you want them, drop me a line if you do.