Session Tempdata vs Cookie for "Remember me" login (CI3)

Hi guys! Just wanna ask if it is good to use Session Tempdata to store the userdata upon login when they wanted to remember by the system. I am using cookie for the whole time since it is recommended by so many developers.

Well, basically, the procedure was to store the userdata in cookie and must set the expiration time (e.g 30days). CI 3 had introduce its new feature to set the session as "Tempdata" with a specific expiration time. Same concept with the cookie I think.

Is it recommended as it is or is it a good practice? What do you think guys?

[Just a programmer] [/Just a programmer]