Your route seems to go very close to St Gallen /Altenrhein LSZR which is a GA airport in a scenic location between the shore of Lake Constance (Bodensee) and the Alpine foothills. From here dependent on weather and your own preference you could choose to route through the high Alps or follow the lower ground north of Zurich.
LSZR is a port of entry for Switzerland, its friendly and efficient, not overly expensive but not as cheap as French airfields. There is a decent restaurant on the airfield. They have AVGAS but possibly not MOGAS. You need to take account of the lunchtime closure period ! The principal concern may be the cost of accommodation and food in Switzerland if you are thinking of spending any time there.