i'm a little confused by this question. you are able to play without a real wii remote and you can use real gamecube controllers through the official (or third party if you're feeling risky) gamecube adapter for wii u. please correct me if i misunderstood what you were asking.
(personally speaking though, i prefer emulating the controller with my switch pro controller. there are more buttons and for games like mario sunshine i am able to freely swap between my R and ZR buttons for full spray and light spray respectively.)
"Keep on gaming, but never become arrogant!"
When it come to Mario Kart Wii, is it possible to still play without a physical Wii Remote, or am I gonna have to switch over to an emulated Gamecube controller?