Sounds like you're considering a trip to the west coast!

GSSP also had some bad luck with weather, but as far as the number of hours of observing, astronomical twilight ends at 10:45 PM and astronomical dawn begins at 3:30 AM. So, theoretically there are 4hr 45min of darkness. Probably 4 1/2 hrs is a more realistic figure. Yeah, not so great. A couple of weeks ago I started observing at 6:30 and by 11:30 had already observed 5 hrs!