Firstly I would say that anything you do around the Tour, especially in the mountains, is awesome. I have done a couple of different options:
Basing yourself in the Alps is great. The fixed point of reference is nice as you always know what to expect and can set yourself up for your rides well ahead of time.
I would say that a camper if within reach financially is definitely the best option but only if you can share the driving with other people. I say within reach as during July they can cost a small fortune but the flexibility to move ahead of the Tour is fantastic.
Failing those I would suggest looking up http://www.alpcycles.com/
as they have been responsible for my most memorable trip where the only thing I had to worry about was getting myself and my bike to the airport and they took care of the rest - even nursing me through a bad day on the bike.
Whatever you do it will be a huge amount of fun. I dont write off the spectacle of the start either as its a good opportunity to get up close and personal with the riders when the sign on.
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