"going to the bathroom" / "going to bed" + special request for native BrE speakers

Learning an L2 as an adult and speaking with people learning your L1 can give you a whole different perspective on the language you took for granted your whole life...and sometimes, you discover things you thought were part of the US-American standard aren't, e.g. "to crack the window" meaning to open it a little bit, which a former linguistics teacher of mine has informed me belongs to the southern variety of American English (how true that really is, I don't know, but she [mid 30s, NY state, US] had never heard it before she came to Virginia, US). [EDIT: Several comments indicate that this example is not true]

So, because several advanced English learners I know have called B.S. on me and I am now fraught with uncertainty, I would like to ask you:

1. Is it possible to go to the bathroom in the woods where there is no toilet to be found?
2. Can you go to bed when you've already been lying in bed and talking with a friend for the past hour?
3. How old are you and where are you from?

My answers:

1. Yes, it is a euphemistic way of saying "to relieve oneself" (another euphemism, oops).
2. Yes, "to go to bed" means to fall asleep, or at least to try to.
3. 24, northern Virginia, USA, now living in Germany.

Special request for native speakers of British English: Since I am studying to become an EFL teacher in Germany, I need to get a better grip on British English. If anyone is willing to answer questions every now and then about British English, please PM me. I can offer my knowledge of US-American English (native language) and German (I have a BA in German and have now been living in Germany 2 years).

Thanks!