It's not the steady trickle of treatable cases that will overwhelm the system; it's the flash flood of CV-19 hospitalisations caused by the entitled morons we call "The Public" that will do it.
So the system's overloaded, so what? We've done our bit and the powers that be have had seven months to put mitigations in place.
Those who are going to die are going to die and, if a foreign power threatened to cause this much damage to the UK, we'd declare war and put the best of our society in harm's way without missing a beat. I'd rather take the hit for my kids (or grandkids if COVID spares me) and I suspect that most people of a certain age feel the same way.
Let's collectively grow a pair and do the right thing rather than the selfish thing.