I'm in a position lately where I'm often the rate-limiting step and I have limited ability to delegate some of the responsibilities that I would like to because I only have 50% of one other person's time, and she's stretched just as thin as I am (if not more so!). There are lots of dependencies and reviews and approval needed by other people, but most of it has to be initiated by me. Something has to give! I can only do so much, and I clearly need to be smarter about the scope and depth of what I'm doing.
I am thankful that there's not a 24 hour work culture here, and I don't want to create it! As a result, even when I'm working evenings, if I compose emails I usually don't send them until the next morning so that people don't see (or always expect me to be) on email outside of work hours.
On the bright side, rumor has it that they're going to find stopgap funding for my project. At least that's a temporary relief! We were told in a meeting that "it's not like it used to be" and "everything is dynamic" (read: no one has guaranteed job security) but I'm busting my butt to make sure they want to keep this project around for the long haul.