I'm your man who can drive your support van ! Did it 6 years ago when my son did LEJoG, non-stop, (other than 6 hrs necessary sleep stops), in a total of 98 hrs.
The thought of doing the trip myself has been in my mind ever since I got into the e-bikes, and accommodation to me would just be a roof over my head, be that light weight tent, youth hostel, glamping pod etc.
Having had my bike pinched recently, that has ironically left me with a spare 500 bosch powerpack, and the plan to replace the e-MTB with an e-tourer only makes the plan a bit more realistic, albeit with some less adventurous slightly shorter trips first, C to C would be a good one for me from my location.
Would agree that the CX motor might be a little less suitable than the ALP, as I found the pedelling through syrup feel of the CX once at 15 mph quite annoying, and in comparison the ease at which this is done on the ALP would only help over longer distances, it's ALOT quieter too. Will have to see how the 42t on the rear cassette copes with the bigger hills, something the e-MTB's 46t +CX had no problem at all with, out of the way Hardknott ! Mind you I did climb the Alpe d'Huez last year on one of the French moustache e-bikes, and that was the ALP motor, in 36t rear gear, and sport/tour mode.