As mentioned above, you are on the wrong forum. There have been similar and/or portions of your planned trip discussed on the Touring Forum in the last year.
The Altiplano is very windy in the winter months (June to Sept), 100 km+ winds are common and it's cold; like down to -20 C at night. Also potable water is scarce and roads are rough/soft. Some cycle tourists on the Touring Forum who crossed from Bolivia to Argentina (granted not exactly your proposed route) seemed pretty happy to have survived. I worked in that are for about 2 years and can't imagine crossing it on a bicycle.