The biggest trays I could use were 16x20". It's also the largest sheets I've ever printed on, and I was constantly worried about creasing the print (I only had 10 sheets — 9 to use, 1 for testing exposure).
Yeah, paper this size gets expensive, and is a bit more difficult for sure. You still managed fine, in my opinion, and the final product as several 16x20 sheets will be equally impressive as a single sheet. Nobody other than photographers will care.
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh