how much does the wind effect you ride?

Quoted message said:

Is it possible to say something along the lines of...

a 170 km ride at an average speed of 22.5 km/hour with a 16mph headwind
is like a 190km ride with no wind

or not?

Less than you think, otherwise riding into a 20mph headwind when you can
only normally achieve 20mph on level ground would be impossible. Having
done three 90 mile rides over the same route last year, average speeds
were circa 18mph with a 10mph tailwind, 16mph with a 10mph headwind and
(you guessed it) 17mph in calm conditions.

Remember though, the cyclist's mantra. There Is No Such Thing As A
Tailwind. There's nearly always a headwind, and if there isn't one you
must be going well ;-)