The requirement of needing a two man team kind of scuppers my initial enthusiasm.
Not done it but done three 4 day stage races in the last few years, 2 solo one as a pair.
The pair thing is the best and worst possible combination, never do it with somebody you are in a relationship with unless it’s rock solid, it’s much easier to tell a mate to f off than a partner.
Understand each others weaknesses, thats what will determine how you finish, know where you can help each other and where you just need to back off.
Try and match evenly and have similar expectations – ie it’s a fun holiday or we are going to podium.
If it’s the latter make sure you have the safe word sorted for “I can’t keep up this pace, lets just chill and look at the scenery”
Looks amazing though, read in a mag about some german guys doing it as a guided more uplifted riding holiday which seemed great.
edit
Hand wash powder to wash gear. They transport your bag to stage end each day.
Buy more gear, best excuse ever to get new gloves and some new comfy bib shorts – 3 days in I put on the 3rd choice bibs and regretted it.