Thank you everyone. Will get more proactive on chasing up. Would have picked up one today Kashinoda mentioned if it had been possible to pay by Paypal. Just lairy of popping cash in by direct debit to a website I don't know.
edit: picked up an Asus Tuf 3080ti for a reasonable (heh at current prices) amount. Just got my first clear day to play and have been giggling a lot at just how ridiculous an upgrade it is. Works fine for the moment on a 750w PSU cos Ryzen 5 and not overclocking, so will have to upgrade that at some point when it's worth chasing more performance. At the moment Time Crisis benchmark reckons system's in top 1% of results uploaded which tickled me a lot too. Massively impressed with how cool the card runs after reading so much about 3080ti's running hot - it's only in a tempered glass case with the 3 fans and it's not broken 65C yet.
Didn't see this edit, nice one!
Not a complete necessity but it might be worth undervolting your card. Not sure if the 3080ti is the same but the memory modules run close / hit the thermal throttling temperature on a lot of the 3080s. Technically they still run 'within spec' but after my 3080 died and came back from the dead I wanted to make sure it had the best possible chance of surviving long term.
Here's some results I posted on OCUK, the TLD
R is it performed better whilst using 70-90W less power and being around 15 degrees cooler.
https://forums.overclockers.co.uk/posts/34769917/There's a video on how to do this this here:
https://www.youtube.com/watch?v=sClh4270yg0That said, the ASUS cards are better than the POS MSI one I ended up with