I just found out! Apparently there is a quest that awards two “O’Draxxia Worker Lodging +1 Expansion Coupon”.
This quest is listed under Suggested Quests and appears to be accessible only when you complete part 1 of the O’dyllita main questline
You also get two Storage +8 coupons and one +1 Stable expansion coupon too for each city.
I have not verified whether it allows up to 6 Lodging (3 Pearl Shop, 2 Quest, 1 Free). The post will be updated once I have tried this.
UPDATE: Yes, the worker lodging stacks with the Pearl Shop lodging coupons.