As far as I know, summer and winter are governed by the amount of sunlight absorbed per unit area, where longer days would increase the temperature along with a higher sun angle.
To elaborate on the title, what I am kinda trying to do is create a planet on which a certain latitude would be able to experience central european summer nights for a duration longer than 75% of the day-night cycle for at least one season, without the daytime becoming painfully hot.
I think a higher axial tilt and a highly elliptic orbit would allow a place that experiences long nights when close to the sun would be able to create this, however the opposite hemisphere would experience rather extreme seasons.
If that already works out just fine, how can this be set up to make other parts of the planet less hostile?
Is it even possible to make a planet that is similarly habitable to earth while allowing one location to experience minimal sunlight while never dropping below 10˚C simply by tweaking the motion of the planet, or would it require the planet to have an atmosphere different from earth/have certain ocean currents/massive heat-exchanging infrastructure?
edit for clarification: The warm season has the long nights, and the cold season has the short nights