You'r e still within mashing temps. You'll still make wort. It will potentially reduce the amount of fermentability so the final gravity is a bit higher. Say 1.022 instead of 1.014. It will still make beer. I don't think mash temperatures affect head retention.
Fermenting/Kegged/Bottled NONE :( I moved to the NW and haven't had time to setup my brew rig since! (but hey, I'm in the Pacific NW so there's so much awesome beer I don't need to brew it as much hah!