That聮s potentially a little challenging. Not finding warm boots, per say, as lots exist. But finding a pair that doesn聮t weigh more than you.
The Deemax Dry Winter BootsYou say hiking, so I assume you do not want the sort of bulky boot that are okay for snowshoeing and other activities. Maybe what you need is something such as 聮s Deemax Dry Winter Boots ($140). They聮re a hiking boot that uses a soft shell fabric to resist water and add some warmth. Thinsulate insulation keeps feet even warmer. And grippy Salomon soles offer good traction.
Take a look as well at ‘s Slot GTX Winter Boots ($150). They have leather uppers with a Gore-Tex liner to keep feet dry. Primaloft insulation adds warmth, and the boots聮 tall cut and flexible cuff is designed to keep out snow. They聮d work well as a winter hiker.
Of course, boots are just the start here. Be sure to wear the right sock combination聴 Silk One Liners ($7.50) would be great. Over those, Mountaineer Socks ($23) for maximum warmth. You may end up getting boots a half-size large to accommodate the thick sock layer, and to ensure the boots don聮t restrict blood flow.
Top these off with a pair of Xenon Stretch Gaiters ($85). They聮ll prevent snow from getting into the boots and also shed snow so the boots stay drier and warmer.
Have fun!