dismal? WTF?
I lived in SAmer for years.
In Winter you'll still get all kinds of weather across the continent, so what kind of weather do you want?
If you want cool weather, then Argentina in general is full of historical sites. Buenos Aires, from a cultural standpoint, is amazing. So is the city of Cordoba (inland). Head on over to Montevideo, Uruguay as well to get a less-crowded feel while enjoying historical sites. If you're doing the hostel thing you should be able to get by OK in Argentina/Uruguay. You mentioned that you don't like 'backpacking' -- if that means you don't like 'hostel-stays' then you're kind of screwed bc hotels are expensive in SouthAmer -- at least hotels that are in cultural/historical areas.
If you want warmer weather...then you need to go up north. Maybe even Northeast to the Guiana's, some historical sites there although not anywhere near as much 'culture' as you'd find in Argentina.
Weather shouldn't be that bad in northern Argentina, though, so between Cordoba, Mendoza, BA, Montevideo, and the Iguazu Falls (on the border with Arg/Braz), you should have enough to fill your time. That's what I would suggest for someone who's not into 'roughing it' which is what you seem to be suggesting. Let us know how the trip goes.
