Mike,
I don't see how crampons would help you out in these conditions. I haven't been as high as SG recently but was climbing Tahquitz last weekend and there were only patches of snow. I understand there's a bit of elevation difference, but unless you have a good layer of consolidated snow, those crampons would seem to be more of a hindrance than anything. I would bring the Microspikes as I'm sure they're be some icy patches/sections along the way. Best advice I think would be to dress accordingly.
Right now isn't exactly winter conditions. Go have some fun, if you do get uncomfortable at some point, then turn around and don't get in over your head. I wouldn't cancel a trip based on a small storm we had earlier in the week. Hope you guys go through with it and have a fun trip.
