Hi James: re trillium
Currently the only new Trilliums being delivered are from Trillium RV (Canada) and they are the 1300 (13') model. Trillium Trailers (USA) are or will be making both a 1300 (13') and 4500 (15').
From 1980 - 1981 Trillium made the 5500 (17') model. There were 60+ of these trailers made with either a single or double axle
. They all had bathrooms and were generally outfitted better then the 1300 or 4500 models.
You will find a surprisingly large portion of the 5500 owners on this forum so if you have 5500 specific questions you should address them directly.
Hope that helps.