To first order I find that cats and monohull's have around the same leeway on a close-reach / broad-reach... 10 degrees or so. I've spent a lot of time in both. If I want to be pretty sure I'll make an upwind mark I plan for 15-degrees of leeway, which just about happens to be the distance between the tip of your thumb and little finger if you stretch your hand out wide, and hold it at arms length.

For Anegada, definitely check out the link I posted above... there's a wealth of local knowledge.