My bike's arrived, and the heated grips were on back order until April-ish, so I've cancelled the grips order and got them to fit some Oxford Adventure grips, which at £65 are £200 cheaper than the Honda ones. They may not have the tidiness of the integration of the Honda ones, but at least I know they'll keep my hands toasty on cold days.
The dealer did tell me that Honda know there's a problem with the factory ones (i.e., they'd asked the dealer if anyone had mentioned it on demo rides, especially as these have been during January), but whether they'll sort it out is yet to be seen
Like I mentioned earlier, I used a laser Thermo on the Honda grips once warmed up on their hottest setting and they weren't even 30deg, when the factory ones on my triumph are circa 50deg
Surely, if you're going to have 5 settings on the factory grips, you want the hottest one to be nice and toasty