Falling for her Guardian by R. E. Butler

Polar bear shifter Storm has guarded the Well of Magic at the top of the world since he was a teenager. Protecting the power source for all magical creatures is an honor he takes seriously, especially in December when Santa’s brother, Jack Frost, tries to corrupt the magic.

Seren’s day goes from bad to worse when her car breaks down during a snowstorm. Spotting a distant light in the woods, she seeks help but slips on ice and tumbles into a portal, landing in the forbidden realm of Northernmost.
Storm, expecting to escort a magical visitor to the Well, finds Seren instead. To his surprise, she’s not only his mate but also doesn’t like shifters! Storm must prove he’s different from the shifters she’s known while defending the Well of Magic and his Yuletide Guardian friends. As danger threatens the Well, can Storm keep Seren safe, or will their romance end before it starts?