I´ve been pondering on how to make my daily winter commute less cold and monotonous...
So I thought why not make it a workout and try to improve my strenght and raise the tempo a bit.
However my commute is not more than about 15 miles both ways so I thought intervaltraining?

I know I could just make it longer by taking a detour but currently I also go to the gym, run, and my job as mailman has me running up and down stairs a good portion of the day and since I also would prefer that life contains other things than exercise, making the commute longer is not really an option right now.
Call me lazy.
Note that It´s not an ambition of mine to become an elite cyclist.
I just want to be able to ride a bit faster.

Anyway, my question is if it´s possible to do some decent intervals and strenght training on the bike with only 15 miles a day?
And if anyone has a good idea on how a week could look like I´m all ears.
Any links or suggested reading would also be welcome.

Thanks!