Is it just us, or did Sienna Miller just have the best style week ever? We always knew we loved her edgy-bohemian style, but this may have been her best week ever, sartorially speaking. At the Golden Globes, Sienna wowed in a navel-skimming, old-Hollywood glamour gown by Miu Miu. She traded the L.A. sunshine for Monday's bitter cold in NYC, suiting up in a shearling jacket, Isabel Marant winter booties, and her signature boho floppy-brim hat. As the weather let up, she took full advantage…