Well, let's see. I use the iPhone app called KataData to calculate these things. If you shoot 29.97fps, 1080p at 8:1 compression (which is good for the work you describe), you should get 1.74 hours on the included 64GB card.
The thing is, you probably don't want to shoot 1080p on the Scarlet because you will be cropping the sensor. This means all your lenses focal lengths are going to more than double. You are better off shooting at 4K HD and downsampling in post, but now you are only getting 45 minutes per card with everything else equal to the above example.



