Basically there's not much chance to get off the beaten track ;-) Travelling south, by far the most scenic roads are on the Argentinian and on the Chilean side of the Andes. The Ruta 40 is just as beautiful as the Carretera Austral in the southern parts of Chile.
People do travel on the east coast of Argentina. There are several places of interest, but it is nothing compared to the roads along the Andes. When in the south of Patagonia the national parks in the south-west are all absolute must-sees. So again this is where all the tourists go. But relax, not masses of them. It is too remote.
Only when we pause to wonder
do we go beyond the limits of our little lives.