I'm not a fan of going to a new place, taking my winter jacket off, and discovering it's too warm for a coat but too chilly without it! A simple everyday cardigan is a must-have for me, especially for traveling and unpredictable weather. It's easy to layer under a coat and quickly removable depending on the environment. Long sleeves and a typically looser fit makes it hard to find a petite-friendly style, though. I found my current favorite at Asos.
I love the versatility of the dark charcoal grey color, the soft vertical rib knit material, and matching color buttons. The shoulder width is just right on me, and I even appreciate the tad bit of extra sleeve length to stay cozy or roll up. I prefer to keep it buttoned up to maintain a little shape, so I like that the v-neck cut allows a little of my tank top underneath to show through. It's so easy to throw on over a bright colored shirt or a patterned blouse.
Asos is online only but has extremely useful features. I've found their fit predictor to be quite accurate for me (typically one size up from the smallest as their sizes run very small). I love, love, love that they use shorter models for their petite ranges. Some of the models are in the 5'4-5'5 range though, wearing petite clothes that are advertised for 5'3 and under, but it's a huge help to see the garments on someone at least slightly closer to my height than usual. Do watch the videos too and see how the items drape.
Asos has a wide range of petite-sized clothing available and they frequently stock new items. Check their current selection of cardigans here, and keep an eye on the model height, fit predictor, and videos to minimize the need to make returns. Stay warm!