In reply to ma-ding:
Have stayed here several times, though not with children. Push chair/cycle friendly paths in the valley, good walking higher, excellent swimming pool, family rooms, really nice May/early June when the flowers are out in the meadows. Check the prices booking with Inghams, probably better and will include your ferry cost. Drive via Luxembourg for cheap fuel on the way, turn off at Ulm and over the Fernpass into Austria.