Chamber orchestras could do loads of baroque and classical era works (I used to attend concerts of a chamber orchestra). A chamber version of a Mahler symphony does seem to miss the mark.
One of my fav concerts I've attended they performed Haydn's 1st symphony. I think that would be about the same number of performers.
That could be a fun thread topic. Do to covid restrictions you have less than 20 performers. What do you play?
If you look into the 20th Century, there are plenty of chamber symphonies --- those by Schoenberg, Enescu, Milhaud, Schreker et. al. Of course, these names don’t draw in crowds like Beethoven or Mahler, so really the bottomline here is money and in a time of such uncertainty in regards to the arts, it seems like it might be a good idea for orchestras to play for the money at this juncture. This is a point that Kyjo has continuously failed to address. Sorry, but Atterberg isn’t going to sell out a crowd of people. That’s just the way it is and one needs to learn to accept this reality.