On "into the night"

[mitake]

In novels and magazines I sometimes find such an expression as into the night, but don’t know exactly what it means or how it should be used. I was wondering if you could answer some questions about the expression.

Question 1: My guess is that sentence (1) means that our conversation continued until the night. Is this right?

(1) We talked into the night.

Question 2: I suppose that into the night can be used with a verb phrase denoting an activity (or state) which has no conclusive end-point ( e.g., drove around Tokyo as in (2a)), but not with a verbs phrase specifying a conclusive end-point of activity (e.g., drove to Tokyo as in (2b)). So I think while sentence (2a) is grammatical, (2b) is not. Is this right?

(2) a. We drove around Tokyo into the night.
b. We drove to Tokyo into the night.


Question 3 : I think that into the night refers to the duration that an event lasts. Is it possible to use into the night as an answer to the question How long as in (3) ?

(3) a. How long did you work in the office last night?
b. I worked there well into the night.

Thank you in advance.

[Rover_KE]

1 and 2a mean 'until it went dark'.

2b is incorrect.

3 is the best version of all, as into the night is usually prefaced by well.

Rover