With the PrimaLuna HP, I believe you can roll in the Tung-Sol KT-120 tubes. Have you tried that? I think you would be surprised how good the LRS would sound using the PrimaLuna with the KT-120 tubes.
In my somewhat larger (14'x28') room, I'm having no trouble driving my 1.7 Maggies with either my 100W Rogue Cronus Mag. II withe KT-120 tubes, or my old SS 200/350W ADCOM. Listening to the same music as you, at moderate levels, both amps do incredibly well. A little larger stage and presence with the Rouge and slightly more dynamics and punch with the ADCOM.
I think the idea that the smaller Maggies need massive amounts of power to sound good, particularly in a small space at moderate volumes, is quit overstated and a bit overblown. If considering a future move up to the larger 3.7i or the 20.7 then investing a Bryston 4BSST or Cubed would be a great match with any of the Maggies. JMO.......Jim