To be honest, the time for sticking by your guns over work week issues is at the interview. If the culture says 80hr weeks are not unexpected, then expect lots of pressure if you don't live up to expectations. I'm just glad Microsoft decided not to hire me out of grad school. :-)

Can anyone suggest a strategy for the first month on the job?

Develop a taste for espresso?

At the beginning you'll be expected to produce fruit. Your first job is to find out what fruit to produce (i.e. what your boss is looking for in order to trust you). Over the long haul you'll want a nice test framework. However, if they really expect to see some concrete progress up-front, then you really don't want to spend all of your initial time on building a nice test framework, but have no working test cases to show for it.