A Lovely White Christmastide by Teah Kemp Weight

Five weeks of matchmaking, four yearning hearts, three kissing boughs, two ex-soldiers, and a fake engagement for a Merry Christmastide.

Some days, Lord Carswell Bingham regrets that lieutenant Daniel Kaye saved his life—especially when his impetuous friend convinces him to take a long, cold journey north for Christmastide. But when they cross paths with the beautiful Haynes sisters, and find they are bound for the same house party, the prospect of five weeks in Westmorland becomes far more enticing.
After three long years, Beth and Julianna Haynes finally have permission from their overprotective father to visit their aunt and uncle—a visit Beth sees as a much needed distraction, while Julianna considers it as their only opportunity to find husbands. Unfortunately, a failed past relationship makes Beth reluctant to love again, even if Lord Bingham does make her heart flutter.