I assume you've checked Costco?
I know they had them for some weeks, though they do tend to constantly change the non-standard items. They certainly appeared to restock (locally) at least once, but I guess once local customers reach saturation point for items like this, out they go.
A caution for you, though. I spent about 2 months last summer waiting for John Lewis to get them back in stock, "next week ". If you're going to get one, and we hit a really hot patch, they will become as common as rocking horse poop or pink unicorns. Don't watch too long.