I know this is older but...
I'm down to 2-3 workouts a week and like you my numbers are doing well.
Sunday
Squat
Press
DL
Tue
Squat
Bench
Thur
Press
DL or Cleans
This has worked well. I'm 52 now. If middle of the week gets busy I'll just repeat Sundays workout once during the week maybe a little lighter.