I would agree with Heather, that the ride as a single climb is not particularly daunting if you have done any mountains climbs at all (the first 2 km's are tough but it eases up after that). Nothing like Ventoux which destroyed my will to live (just kidding)

I did the ride a few days before the Tour came through on a glorious 23 degree morning. It got up to 30 later in the day and saw alot of cyclists suffering up in the heat.

I stayed on the mountain in the village of Huez which is at about the 11km point. It was perfect as my wife could snap my photo/video as I was going. In April/ early May you may have difficulty getting hotels on the mountain or on the way up because that is mid season between skiing and cycling so I think alot of hotels shut down for a time. Plus there isn't really alot to do after dark, when we were there were tons of Dutch camping and partying all night, but would not be the case at other times