The extra 10mm might make the 10 degrees work. I'll look at the bike more this weekend. I've got a 16 degree 90 mm stem that's oversized and a 100 mm 6 degree stem, so between the 2 of them I should probably be able to figure out where exactly I want the handlebar.

I guess I could just buy a new oversized handlebar, but the stem seems like a cheaper part to switch.