Anything less than an 8×10(or 9×9) could be cramped when pitched in storm mode.
You can't even sit up in an 8×10 if you have it in a tight a-frame or flying diamond.
Another thing to consider, a cat tarp makes for a less floppy/flapping pitch, but at the cost of flexibility. People tend to only pitch cat tarps in a-frame mode, but sometimes a flying diamond, half pyramid or other pitch may be more appropriate for the site location.
I'm split on which I prefer:-(

