Ok, have a 12"X18" sheetcake ready to be frozen until I'm ready to start shaping it for a 3-D cake. Not sure if I'm better off freezing it in the pan or out? Should I just wrap it in the pan? If I do this will it be hard to get out later? I treated my pan so I know it will just fall out at room temp.
If I take out of the pan what should I place it on to freeze it? Maybe just a cake board?

If you won't need the pan in the meantime, it lends itself to protecting the frozen cake. I generally remove the cake, add a layer of plastic wrap to the pan, then flip it back in the pan and cover it well.
Works great for me.

Sounds good to me! Thanks so much.

If by chance you can't get it out of the pan once if has been frozen in there, you can just turn on your oven and put it in there only to warm it up just a bit. It doesn't take too long at all.

You may not even need this tip. It very well could come out fine on it's own, but just in case it doesn't.....

Thanks for that tip too. Makes sense.

I just flipped the cake out of the pan, then placed a layer of wax paper around the cake, then placed the cake back in the pan and wrapped the entire thing in plastic wrap.

I feel pretty confident this will work. Appreciate everyone's help!