Apr 26, 2014 - 8:28 AM
Thanks for posting here. Unfortunately no experiences have been shared yet; hopefully someone will come across this thread later. I have no experience with campervans myself. I suppose an advantage is the freedom of moving around without packing and unpacking too much. Also you may save a bit of money compared to mid class hotels. A disadvantage could be driving on narrow winding passes with a vehicle you're not familiar with. I am not sure if you have planned that.
Note that the higher passes could still be closed, or temporarily closed in June, due to snow. Although usually most of them are open, and with the warm Winter we've had in Europe it won't be a problem I guess. It's just something to keep an eye on. Our section about traveling by car provides lots of information about how to drive in the mountains, road conditions, etc.
Not booking accommodation in advance is fine in low season. Early and mid June are still low season. Of course, if you want to stay in some small popular village with just one or two hotels or one camping, it could be fully booked. Most hotel booking sites we refer to in our hotel section allow free cancellation until the afternoon of arrival, so in such case there would not be a risk in pre-booking a few hotels you would like to stay in.
If you're going to make trips by trains, cable cars or boat (actually it's a must to do such things in Switzerland) a Swiss Half Fare Card will save you money.
I hope this was useful!