I disagree here - there's definitely some minimum amount of resources you want to use to make k8s worth it memory- and CPU-wise. You may be able to get by with 1 CPU and 1GB of RAM for your master (which is just coordinating, not running any workloads), and there's some overhead on the workers as well.

I've been looking at running k8s at some raspberry pis at home, but anything smaller than the recently released 4 is just not worth it IMO (though I've seen several people run clusters of 3B+s).