Couple things I learned at the tire test...

1) That little arrow doesn't mean a damn thing. Has some other meaning that I can't remember, but not what we all think it means.

2) I've been close, but need to run a couple more pounds than I have ever run because I let the tires roll too much.

There is a separation line that you can just barely see in this photo, just above where that arrow would be pointing. But probably 1/4", or so, higher than the tip of the arrow... Hot Rod - Michelin Pic

That's all the further the tire should roll. That's the separation line from where the contact rubber is bonded to the sidewall rubber. Past that and you are into less sticky material.

Basically I have been running to about the arrow like you... forever. I've never taken temps, but by your temps, it looks like if you raise the pressure a couple pounds you will probably get the tire over where it should be.