I teach 6th, 7th and 8th grade and have my students once a week for 70 minutes.
I've broken down the course into covering about two units a year.
6th - Consolidated Unit 1, 2 and the beginning of three.
7th - End of 3 and 4
8th - 5 and 6
I agree that consolidating Unit 1 is a great way to gain back some lesson time. Once you get into the other Units it's hard if not impossible to take out content and skip lessons.