High loads causing node to become NotReady?
Turns out one of my pods was consuming all the CPU on the node. Causing kubelte to become unresponsive. I've set a limit on the pod's CPU-time and that fixed the issue. Also, added a kube-reserved setting to ensure kubelet gets the CPU-time it needs.
If the load is growing because of growing amount of Pods, you can try to use Node autoscaling. Here you can find the instruction about it.
If only several Pods consume all Node resources, then the only way is to use Nodes with bigger amount of CPU and Memory