When do we think the M1 iMacs will surface. Wife needs a new iMac as the 2011 is creaking.
About 2 weeks after you give up and buy an Intel iMac, of course
Seriously, though, the short answer is that nobody knows, and while the rumours sometimes get the “features” right, they’re rarely reliable on timing. It hasn’t exactly been a typical year since Apple announced the “2 Year” switch. Plus, this time round they’ll need a brand new processor: the M1 gives the higher end Intel Macs a run for their money, but needs more cores, more RAM capacity, more I/O, better GPU, better multi display support...
My guess would be that Apple’s priority will be the higher-end MacBook Pros, since they are likely the next biggest sellers and are being embarrassed by the entry-level M1s. But that’s just a guess.
If your iMac is actually failing then I’d second the Mac Mini suggestion, with a 4K screen.