I really enjoy the Leslie Sansone "Walk Away The Pounds" series. You can choose a 1,2 or 3 mile walk and its very low impact. I'm sure you could manage the 1 mile if you are coping with the dog walks. We live in a small apartment and the limited space hasn't been a problem.

The program is basicaly walking on the spot, knee lifts and kicks. If you are new to exercise (like me!!) it will give you a great workout and is really gentle on an unfit body. She also introduces light handweights to help with toning.

I believe they are widely available in the States and Canada.