1. How many years was Chell asleep in Portal 2?
2. How is Chell still alive in Portal 2?
3. Is Chell dead Portal 2?

How many years was Chell asleep in Portal 2?

It seems likely that she has been asleep for perhaps 20 years (If this is correct, it could link the timeline of Portal 2 with Half-Life 2: Episode Three).

How is Chell still alive in Portal 2?

Chell reappears in Portal 2 where she is reawakened by Wheatley. She and Wheatley attempt to escape the laboratory, and in the process accidentally reanimate GLaDOS. GLaDOS eventually recaptures Chell, but fails to kill her due to her lack of neurotoxin and turrets.

Is Chell dead Portal 2?

at the end you see the turrets deploy and 3 seconds before they start singing, in the game it states that the turrets have 3 seconds before firing, Chell is dead.