This is not the MuPDF viewer itself, as that requires a GUI library and
various hooks that I don't understand. Nevertheless, it is possible nowadays
to cross-compile console-based DJGPP versions of MUTOOL.EXE and MUDRAW.EXE,
which both can be used to do various things, including write pages from
the PDF to image files (e.g. PNG) for viewing separately.

This may or may not be "better" in some way compared to XPDF or Ghostscript,
but consider it at least another alternative to try, in case it somehow
works better for you.

P.S. The sources and binaries were compressed with 7-Zip using "only" 16
MB dictionary, hence you should be able to painlessly unpack without
issue. (I could've used better compression, but then anybody with less
available RAM would have to swap like mad, which is far from ideal.) It
should be small enough, at least to download. If you want smaller .EXEs,
try "upx --best --lzma" (avoided here because it would've hurt compression
across both files, which both use the same guts). Also, I don't really
recommend unpacking the sources in DOS. In fact, it probably won't work
(8 subdirs limit) and is too big to study all at once anyways. I've not
looked, just very very minimal patch to compile it and only with very
little testing.