If you haven't yet, I would try disabling the XMPP/DOCP profile to see if that passes a test. This will tell you if the RAM is just dead or if it's degraded a bit and can't hit the same speeds as it did before. If it does pass, then re-enable that profile and try downclocking or loosening the timings a bit to see if that'll work.
Failing that, you could try increasing the voltage slightly (like +0.05V, I wouldn't go above 1.4V), but I'd be careful on this front to not cause anymore damage.
Sucks that this happened right now, but IMO it'd be better to sacrifice a slight hit in performance than to buy RAM by itself at these premiums.
I mean, like most reviewers they test their games at ultra/very high to isolate the GPU performance. But realistically you shouldn't be expecting to run those settings at 1440p/4K for a budget card like this.
More 8GB cards sucks if that's what gets released, but it's not like you can't game at all without more VRAM. Just turn down your settings till a better deal comes along.