Ladies, please help with the sizing for the Follies Spikes in 100mm. I tried sz 40 in boutique, they were a tad roomie in the heel. Then I tried 39.5 and 40 nude with crystal spikes in bergdorf, 40 felt too loose and 39.5 a little tight in toes. But! It was very very cold in Bergdorf's! Boutique has only 40 available and its final sale