Sorry chaps, November in Argentina/Uruguay is equivalent to June in the northern hemisphere, a touch early for a beach holiday, though perfect for the rest of the country. Punta del Este is great in season, which starts in December, but out of season it's as dead as a Dodo.
Personally I would spend the four days alloted to Uruguay in Patagonia, and do both Calafate and Bariloche, squeezing in Valdez Peninsula
if at all possible.
Here's a two week itinerary I suggested to someone a few months ago:
Buenos Aires BUE (of course), Mendoza MDZ, Bariloche BRC, El Calafate FTE (Perito Moreno Glaciar) and Trelaw REL (Valdes Peninsula).
1 Arrive BUE overnight flight
10 EFE (visit glacier)
12 REL (visit Valdes Peninsula)
The Argentine tourism website
is a bit complicated, but very complete:
The Argentine Airlines
site will give you a good idea of routes and prices:
By the way, we took a supremely comfortable overnight bus
from BUE to MDZ with full length beds, dinner and breakfast for just US$ 23.00 (in 2005).
Please look this over and keep in touch if you need more advice.