The local authorities along the routes have been putting lots of info online about ask these plans, so getting detail from them / tourist offices is your best bet.
We found the staff in Harrogate and Hebden bridge seemed very well informed, so I think this reflects the effort going in to telling potential tourists what they need to know.
Parking is certainly the big issue, and there was some sign that park n ride on buses might be available into Harrogate. I don't study it cos we plan to peddle in. You need to look at what side to approach on, with the road closures.
We are going to park and ride our bikes in, there seems to be plenty of road parking on the motorway side of Harrogate, a few miles out ... so we expect it to be feasible We did it for Ventoux stage when they reckon 3/4 million folk clamber in, so I reckon we can do it here too!