Has anyone doubled this recipe? Can I make it the night before I want to frost my cake? Thanks this is for a wedding

I haven't made this exact recipe, but it is a variant of ABC, which is fine to multiply as much as you want.  It is also fine to make the night before.  If you refrigerate it, just let it come to room temperature.  I would mix it up again just before using.  

That recipe is very similar to one I posted years ago.  You can make this recipe w/o having to deal with doubling and have a great icing:   https://www.cakecentral.com/recipe/22469/2-icing    No problem making it days before and simply stirring it before using.  Can be kept at room temp (about 70-75 degrees F) for several days or stored in the frig.   

Thank you so much