If you slip, your wing is operating at less efficiency, so a lower coefficent of lift, so you need more speed for the same lift, or more AOA at the same speed, so my guess would be a higher stall-speed.
A better question would be what are you doing slipping with a high AOA/low-speed? It seems like a great way of getting yourself killed.
When I do a slip to lose altitude on final, and I need to lose as much as I can in as short a distance as I can, I go full flap, full rudder, and keep the speed up, since drag is speed^2. I think J. Mac McClellan (or was it Richard Collins?) wrote this in Flying Magazine a long time ago as more effective than going slow and waiting. You can go above or below best glide speed to get rid of energy faster, but going faster is safer since you're not as close to stall. Just don't get too close to the flap limits.