Is it best to put fondant on a cold cake that has been refrigerated or best to do it once the cake has come to room temp.?

My personal experience is it's easier to put it on a cold cake.

I have no trouble with applying it to a room temperature cake. But I will try it on a cold cake to compare the difference.

I put my cakes - frosted - in the fridge before I ice it and put fondant on it. Then back in the fridge after I put on the fondant - and inbetween decorations.
I find it works very well when I want to put a fair amount of icing on my cakes that will have fondant on them.

Some people use just a thin layer of icing before putting on fondant - icing can go bulgy/bubbly if there is too much.. (when I do it)
But I like lots of icing - and putting it in the fridge inbetween my steps has worked wondahs! LOL (IMOP)