Ok so I'm thinking August 28th to September 1st to make the most of that bank holiday, meaning 4 days off work. That gives people the weekend to get to me and then the weekend again to get back. Anyone arriving early or leaving late can do some bonus riding in the area.
I will plan something like the following:
Day 1:
Warm up at Gurnigel loop, followed by Les Mosses, Pillon and Jaun mountain passes. Potential to jump off a mountain with a parachute at Jaun.
Day 2:
A day going through the French and Italian passes, entering France via Forclaz pass, and returning via the via the Grand Saint Bernard pass.
Day 3: Big day of 370km!
Gruyere National park - Valais - Verbier pass - Zermatt (see the mountain on Toblerone packets) - Centovalli pass - Titcino/Italy overnight stay
Day 4: Another ~350-400km day!
Return to Gruyere via Lake Lucerne, the Susten, Furka and Grimsel passes and Interlaken (surfers in the river and great tunnels).
Day 5: Length can range from 200 to 400km depending on how everyone feels by this point.
A mild end to the week exploring the lakes and passes in the Jura (of Jurassic park fame) mountain region.
This means staying for one night in a hostel, and the rest at my house.
I will probably be importing a motorcycle here next year so I can maybe do the UK to Switzerland leg with others if they want to.