Storing and querying rolling data in PostgreSQL
All things considered, I would go with option 2. Dates will be evenly selected on, but I'm going to guess that for a given query only one or two date partitions will be involved. It's a shame you can't cluster on geolocation and partition on date, which would be ideal. Elevation tends to correlate with geolocation anyway, if the bounding boxes are sufficiently small.

Given the choices available, cleaner data operations and avoiding a daily vacuum is a good thing to have.

Delivering selects may be faster with option 1, though I suspect it will probably be a wash. With option 1, records with the same date and elevation are placed near each other in one big clustered index. With option 2, records with the same date and elevation are placed near each other in many smaller clustered indexes.