Is it really worth using your Avios for this?
I flew that route in both directions in Club World back in May/June this year.
I doubt it's worth using up your Avios for an upgrade from WT+ unless you really want access to the lounge at LGW. You will be in the Delta lounge in MCO, and food offerings there are meagre. Granted, it is otherwise quite comfortable. I suppose you get nicer food in club as well, although I wouldn't describe it as outstanding.
Be warned that the "bed" in Club is a very narrow affair, and if you're in an aisle seat you will have people climbing over you. The Club cabin in general was in a less than perfect state of repair as well.
So at least for a daytime leg, if it was me, I would save the Avios for something else.