I did the following set up when my life got pretty hectic a while back, and managed to hit some great PRs while having a lot of schedule flexibility:
Main: 5's pro 3-5x5 FSL
Assit: 25-50 of each category (exercises depended on time and how I felt)
Main: PR sets, 0-3x5 FSL
Assist: 50 ea
Conditioning: bike only for 20 minutes a couple times a week
Here is the key:
On Sunday I would try to plan my week depending on what was going on. If I could lift all 4 days then great. If not, I would combine days so that I would only hit the gym 2 or 3 times a week. I would also change days during the week if something happened. Just about every week was different, but I made sure to hit all 4 lifts at some point every week.