Help with cardio routine?

Trying to drop 25 pounds by Christmas. I'm 140 lbs and 5'3", my goal is 115 and to hopefully reduce my saddlebags.

Two days a week I do HIIT for 15 - 20 minutes in the morning, and 30 minutes of cardio in the afternoon.

3 days a week I do 30 - 45 minutes of intense cardio. Normally, I play Dance Dance Revolution. I do it on the hardest level, with the arrows moving at 2x speed, for about 35 - 45 minutes straight. I never change the song so there's only about 30 second between each song, and during that break, I keep moving (usually doing jumping jacks or jump rope, unless I have to get a drink, and even then I walk around my bedroom while drinking) Even when there aren't arrows on the screen I dance around on the mat. I jump and move a lot. My heart rate is high the whole time and I sweat so much. My legs are burning during the entire thing, too. It surely makes me sweat more than running in place or rope jumping for 45 minutes ever has. The calorie counter says I burn 1000 calories, but I know it isn't that much. I always guess it's between 300 - 500 calories, half or less than half of what it estimates. And, I also mix up my cardio. Some days I'll use my stationary bike, others I'll do DDR and rope jumping, or just rope jumping or running in place...etc etc.

So is 30 - 45 minutes good, as long as it's intense? Most people tell me 60 - 75 daily and I don't have time for that.
Also, how many calories should I eat? My BMR, including exercise is about 2200 - 2400.