I'm of the mindset of always doing as little as possible to acheive fat loss. Keeps you from getting frustrated with a packed schedule and also gives you some place realistic to go when fat loss slows down. It's just a matter of slowly adding to a calorie deficit.
I'd make sure your diet is as good as it can be before committing yourself to tons of cardio for fat loss purposes. Once you've done all you can with diet without dropping your calories too low, you could add a few extra days of different types of cardio training into your split (keep your interval training in there and work on upping intensity, but mix it up and have fun

). No need to go insane trying to fit 2 hours of cardio into every day. Just start off with 3 extra days of doing 30 minutes something and add what you need from there. This could include swimming, group exercise classes, plyometric routines, even going hiking. Heck, if you have a gym like mine with TV's at every cardio station and find yourself watching TV at home go do it while walking on an incline and jumping rope during commercials (done that before when I'm restless...LOL). Mixing it up will keep your body from acclimating to a particular activity, give you lots of little goals to set (and chances for acheivement, too!) and give you a wide range of things to do to burn extra calories.
Beyond that, give your body at least one good rest day a week and you should be golden.