This is certainly one of Beethoven's most famous piano works, and has possbily been transcribed or arranged for almost every combination of instruments one could imagine. But this arrangement might be a first, for all we know.
This score is for one Bb soprano sax, two Eb alto saxes, two Bb tenor saxes, and one Eb baritone sax. There is really no good way around using this particular ensemble. No part is expendable and no part is completely within the range of another sax. If there were to be any substitutions, a clarinet could be used to sub for the soprano sax, and a bass clarinet could be used to sub for the second tenor sax. The latter substitution would change the texture significantly.
The challenge here will be breath support, and keeping the triplets in rhythm. The triplet is carried most of the way by the soprano, but the first alto has a couple of lengthy triplet passages as well.
This should be a fun and familiar concert piece that shows that the sax can play classical/romantic music as well as any instument.
MOONLIGHT SONATA, by Ludwig van Beethoven arranged by Tom Kirkland for saxophone sextet of one soprano, two altos, two tenors, and a baritone, comes in a pdf file of 1257k, with a twelve-page score, one three-page part, five two-page parts, and a license page, twenty-six pages in all. Performance time should be about 5:30.