The whole game?
I mean, probably most people can do that, but it would take more time and effort than it's worth.
Just casually reading notation I can follow short variations in my head... if there are no complicated tactics then somewhat longer variations, but other than that I'd like to see it on the board.
IMO the best type of training always tries to mimic your performance.
In other words if your "performance" is OTB, then practice calculating by doing analysis (obviously without moving the pieces) on a real board with puzzles, studies, or whatever. (Obviously you can movie the pieces after it's over to check yourself.)
I tried some blindfold games as a way of training calculation and honestly it wasn't that useful for me.
You mean without a board? Good joke.
No it doesn't. Low rated players who can't do it very well think it sounds like a good idea but it doesn't work.
I had a friend who could play up to 4 games blindfold at once.
When we played 1 on 1, sighted, he sometimes miscalculated things.
I don't think they're related all that much.
Plus when I was training blindfold with a computer program (I typed the moves and it responded with notation) I had an amazing thing happen... sometimes immediately after making a move I'd "see" it was a mistake. Just like with sighted chess when you don't see the tactic until after you moved. Weird.
How long did it take before you could follow a game by just reading the notation?