Would skiing travelers be able to return from La Thuile to Pré Saint Didier and board a bus to continue down the valley to Aosta directly? Where is the bus terminal in Pré Saint Didier? Or, does SAVDA's route take you back to Courmayeur to have catch a another bus to Aosta ?
The Linea 160 SAVDA/SADEM bus goes from Courmayeur to Torino Porta Nuova F.S. and back. Its intermediate stops include La Thuile, Pré-Saint-Didier, and Aosta, which are covered by one same bus. This means that you do not have to change at any point during this journey. However, if you wish to continue further than Aosta you will probably have to change bus.
Alternatively, the SAVDA/SADEM Linea 207 bus also goes from La Thuile to Aosta., via Pré-Saint-Didier.
For more up-to-date information on the SAVDA/SADEM buses see their timetable page.