Get a concept 2 rower and learn to suffer on that 3-4 times a week. Vary between longer steady speed and shorter interval sessions. My sessions run 10-20 minutes. A rower is zero-impact cardio with strength training in one. Also spend 15-20 minutes every single day on a full-body stretching routine. Less than one hour total for the whole workout. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.