The schedule above has worked well for me. I used to cane it both directions for about 50 minutes (20km) each way when working in the city, for four days a week M/Tu/Th/F. Some non-trivial hills along the route. Developed a case of overtraining which could have gone ugly (loss of job?), from which MikesBytes saved me with his advice at a time when we both inhabited another forum before coming here. Loss of sleep, poor performance etc as noted above. Keeping the HR below 130 on the return trip made a big difference. Thanks again MB.

From a training and fitness perspective, I've found less is more (... although now that I add it up, when I include the long Sunday Morning ride I am actually doing more hours in total, just not digging so deep all the time.

Duh!)
Fenner's schedule talks about 90-120 minute training rides once a day on the Tues & Thurs, so I'm actually doing a lot more than he suggests. So if I'm not feeling so strong for the return trip I don't let ego get in my way and am happy to soft-pedal it.
Proper on-the-bike nutrition (again Fenner, with a few twists gleaned from riding buddies) has much improved my riding speed at the back end of the long rides, so I'm actually working harder for much much longer with less fatigue, and I feel pretty good afterwards too I must admit... recovery is so much better. Spacing things out like Fenner suggests works really well and the final piece in the puzzle was the light effort recovery week every third (ie, 2 "on" followed by 1 "off, 2 "on", 1 "off", rinse and repeat).
When I come back to the first "on" week in the cycle I can tell that I've recovered well and I can go harder than the same week in the previous cycle. Tried stretching it to 1 in 4, didn;t work nearly so well.
YMMV, especially if under 40... 1 recovery every fourth week will probably work for you.