This is going to vary widely from individual to individual, and not even consistently with the same individual. Exhaustion and low blood sugar do change behavior, ya know.

I think that setting an expectation is pointless, and not getting the response from another hiker that you had hoped you would get is also pointless.

However, after many years of hiking, my experience is that the most frequent, and warmest, and most genuine greetings occur on winter hikes among passing individuals or very small groups.