The problem is not a service or max ceiling, but when you’re surround by mountains,you need power and lift to quickly climb, and protects against downlifts.
You also have to constantly picture where sinking and rising air would be. I did a reasonable amount of mountain flying in an 85hp Cessna 140, and on a hot day I’d usually seek out thermal or ridge lift to help with the climb. If the wind started to pick up, so did the risks – severely. I remember crossing the Sierra Nevadas when the weather moved rather faster than had been forecast, and it was slightly terrifying (the kind of turbulence that feels like the angry hand of god slapping the plane around, and needing to very carefully pick a path that would avoid rotors/downdrafts etc)
The Samedan briefing includes a note on which side of the valley to fly in various wind conditions.
Service ceiling is a function of available excess power and rate of climb :)
A Super Cub 150HP should deliver around 500 fpm at 10,000 feet – quite respectable for light normally aspirated GA.
The 90HP Super Cub boasts a service ceiling of 15,000 feet – but I suspect that is optimistic.
I should add that mountain rotors will exceed most GA performance.
Mountain wave and slope wind effects will give more up and down movement than light GA is capable of. So fly like a glider, choosing your track.
Rotor is something else, the part of the wave to be avoided by everything.
About 70 years ago, a glider in California was torn to pieces. The pilot just opened his parachute, he didn’t have to bail out. The rudder pedals were caught in his feet, but the rest had gone. It was not overdosed.
More recently a fatal glider accident in Scotland occurred near the time and place a C172 was turned upside down, and lost several thousand feet. The pilot recovered control, and an engineer check showed no airframe damage.
