I think you'll be waiting a very long time. If the 3090 is only 11% faster than a 3080, where does a 3080 Ti sit? 7% faster for £1000+? We know at this point that Nvidia is launching a 20GB 3080 soon too, so the potential VRAM argument is out the window. No doubt the 20GB 3080 will also be pushing £1000 itself, leaving even less room for a 3080 Ti even price-wise.
I think the Ti comes into play when Nvidia switch from Samsung's 8nm process to TSMC's 7nm process in the spring as speculated. I've just watched Linus's review, Nvidia are claiming the 3090 is for content creators, so when the 3080 Ti surpasses it they'll say that was always going to be the case.