Hi J.,
It is a bit odd that homework carries over the weekend. I wonder if the teacher is concerned about families' busy schedules during the week and thinks it would be easier to catch up during weekends?
Anyway, my youngest has faced similar requirements and we found the best way was to stick to a homework schedule, even if it is on Sunday. If you and your student study a little bit all week, skipping Saturday and reviewing on Sunday should be pretty straightforward. However, if you wait until Sunday to do everything...well, it'll just cause massive stress and long term learning won't happen. It's the first grade version of cramming. I say that as both a mom and a teacher of 15 years.
Perhaps it would help to have everyone in the family study something of their choice during the Sunday review session. That way your student won't feel like he's missing out on something fun. This has worked very well for my family, particularly during summers. We each pick a theme and dedicate time each day for study. For example, this summer, I'm reading up for a Civil Rights course that I teach, my oldest and I are reading "Great Expectations," which is required summer reading for him, and my youngest has a workbook and a "read for fun" book. When it's study time, we all sit down and work on are various projects, helping each other as needed. Everyone learns and everyone is included.
Hope your meeting with the teacher goes/went well.