So you don't care that Russian subs are mapping out our undersea cables, which can only be to interfere with them at some future point?
So you don't care that Russia is involved in the people-trafficking of illegal migrants to the UK?
So you don't care that Russia is involved / facilitates the cyberattacks on UK organisations and drone incursions at airports?
Putin doesn't have to carry out a full-scale invasion of the UK to fuck us up. Being an island may offer some protection from physical invasion, but it makes our supply lines vulnerable (e.g. we don't produce enough food to feed ourselves). And given how far modern drones can now travel and how difficult they are to stop, being an island offers no protection at all.
We are already at war with Russia, just not a conventional open war. The Cold War never really stopped, and now we're in a Hybrid War, where we are attacked by non-military tactics to weaken us.
You claim to "not really fancy a "winter of hardship to beat Putin" ". How hard do you think winter will be if he launches deniable cyberattacks on power stations, hospitals, banks, air traffic control? Abandoning Ukraine wouldn't stop him doing that, you do realise that?
Wake the fuck up.