You aren't going to win any strong man competitions with this routine, but if you are just trying to keep your body in shape there are a few things to consider.
1) Abs are made in the kitchen. You need to spend a lot of time on the treadmill to burn off a single doughnut. If you skip the doughnut, you can skip the treadmill.
2) Each morning I do one set of pushups, curls, overhead press, lat pulls, and triceps. Probably takes less than three minutes. Back when I went to gyms, I would do 3-4 reps of 5-6 different lifts about twice a week. With travel time, rest between sets, and a shower that would take close to 2 hours per trip. So if you do the math, I am getting 7 reps of 5 exercises per week with a total time of about 20 minutes now vs 6-8 reps of 5-6 exercises per week for a total time of 4 hours. And if you do the math on total elevated heart rate time, the numbers are probably close enough, as there is usually a 10-20 minute recovery period after each workout. If we assume 15 mins, you get 7x15=105 minutes vs 2x(~40+15)=110 minutes. Basically in the ballpark even if the numbers are off a bit.
3) More importantly, I rarely skip the short workout whereas I would regularly skip the gym workouts. I definitely don't feel as good as I did after a gym workout. But I never feel as bad as I did after skipping the gym workouts for a few weeks in a row.
It is worth mentioning that I am not a disciplined eater. So I do go for a 3-4 mile run once a week, a short bike ride 1-2 times, and usually mix in another outdoor activity or two on the weekend. But just in terms of substituting gym time, I think the short daily workouts actually get you most of the way there. I am probably going to start mixing in an afternoon routine as well because it has been such a good development.