Route De Grand Alps

Tony Defy2

My wife and I are planning to cycle the Route De Grands Alps (Geneve to Nice) this July. We have already booked our flights to Geneve and return from Nice. Please can anybody advise us on how best to get from Geneve airport to the start of the route at Thonon Les Bains. Is cycling from the airport feasible or is it best to get on the train? Any suggestions would be very welcome.
Also, can anybody advise us on where best to collect bike boxes in Nice for our return flight home?
Many thanks
Tony & Andrea