For a non-turbocharged piston airplane, does cruise altitude really
matter? I made a c

For what it's worth, I've had to go (had to? Like that was a bad thing!)
Boston to Chicago a goodly number of times in a Mooney 201. Westbound almost
always it was at one of the lower available altitudes, and ALWAYS involved a
fuel stop in northcentral or northwesteern PA.

Eastbound, it was almost always at 11,000 feet, and nearly always it was
nonstop, with me landing with at least one tank half full (my personal
if-you-land-with-less-gas-than-that-you-screwed-up) minimum reserve.

It had everything to do with winds aloft..