Check out Cycling Holidays in Alpe D'Huez - Cycling Accommodation in Bourg D'Oisans for somewhere to stay if needed and excellent advise on all climbs you can get to from Bourg.
Couple of things I’d add to all of the above, few points about the tunnels. Bring a front light, some of the routes like Notre Dame have tunnels cut through the mountain and there are no lights and its pitch black. Secondly watch out when your descending fast into a tunnel, with the temp change your glasses will mist up instantly and dim lighting mean you can see f*"k all. Scared the absolute be jaysus out of me first time it happened. Lastly bring a light jacket or an extra layer for the descent from Galibier or similar high peaks. Last time I was there early June it was 26 degrees in Bourg and -2 and snowing top of Galibier with 9 ft snow dirfts either side of road.
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