I assume, if you purchased it at Costco in a pot that it is a Hawaiian HIbiscus. They are not hardy here and will have to come inside. 

Expect it to lose some leaves but just keep it watered and in an area where it will get the most sun. In early March you can give it some plant food and it will probably re-bloom. 

https://www.monrovia.com/be-inspired/your-complete-hibiscus-care-guide.html

Before you bring it inside, be sure to wash it down with a mild soap solution to kill any insects living on or in the soil.

https://extension.umn.edu/yard-and-garden-news/bringing-houseplants-back-inside#:~:text=Gradually%20reintroduce%20to%20the%20indoors,a%20little%20at%20a%20time.