Don't rule out Annecy in the Alps. Stayed there last year and it was a superb base for cycling. All the way along the west side of the lake and up the valley to Albertville there is a superb cycle path (an old railway line), so you can quickly get away from the traffic without any strenuous climbing. Every valley to either side of the path is rideable, and I took in the Col de l'Epine from Marlens (a 500 metre climb over about 8km that featured as a Cat 1 climb in the 2012 TdF) as my first Alp and rode several very quiet roads near Chevaline and Doussard at the South end of the lake. There are big Tour de France rides nearby up the Semnoz (was an HC climb in the 2012 TdF), the Col de la Forclaz and others with great views back over Lake Annecy, . I'm going back later this year to try the Col des Aravis and the Col de la Colombiere, which are about 600 and 800 metres of climbing respectively. Annecy itself is a beautiful old town full of waterside restaurants. We stayed at Doussard at the South end of the lake, and are going back to the same place again. Can't recommend it highly enough.