Sira Cogtree has been introduced to Frostfell by Jarith Icewing and wants to share the holiday with her home city.
Climb out of the basement and speak to Meg Gingersnap. She'll send you out to cut a Frostfell Tree for Maldura. Yes, the tree is three times your height, but Frostfell magic will allow you to pocket it.
Return to the workshop's basement and use the giant snowglobe to travel to Maldura.
Take the tree to a spacious location (in the Palace of Unity foyer at 133.57, 62.08, -1.03 ) and click on the glowing spot to set it up.
Next, find Sira and Jarith in Maldura. They're by the entrance at -161.74, -7.55, -36.01 . Speak to Jarith to finish.