Hi,

Im using a wilton recipe for classic buttercream but since my kid cant have dairy I substitute vegan butter. I always need to make so much (at least it feels that way) and this year Im considering making it ahead of time. Is it ok to make ahead of time? Would I just refrigerate it and then bring it back to room temp?

Thanks!

yes

but i would wait to add the vanilla until right before you're gonna use it -- if you don't mind taking it for one last spin in the mixer --but it's fine either way

Certainly.   Also any leftover can be frozen.   Just defrost, stir well then use :)