Out of respect, I omitted to mention Berlioz' Roméo et Juliette, symphonie dramatique, which is really a sort of cantata-oratorio-thingy. His most extended concertante work, Harold en italie, is of course a real symphony, in four pretty-much-standard movements, notwithstanding the viola obbligato which dominates the first three. ("Finale problem" strikes again!)

I thought about Stravinsky's Symphony of Psalms, but by jigger I actually classify it as a choral symphony. I'm assuming you have no problem with Copland #3, which saves the sonata form for the finale, or such as Barber #1, Harris #3, and Sibelius #7, one-movement works with internal symphonic structures.

And of course there is that one item I ought to have mentioned, but blocked because I have seen and heard it, probably because of its egregious awfulness as a production number in a movie that I only ever watch for the presence of a few of the performers. Its title, amazingly enough, has been re-used in more recent days for something I haven't heard and don't want to hear. There's no point in listening to likely crap when I haven't yet heard all the extant JSBach cantatas.