For those (like me) who followed Oo.oO's and John Appleyard's advice and have been updating makefiles or changing fortran installations for the past 7-8 years, GNU finally made -static-libquadmath a link option.

gfortran -static-libgfortran -static-libquadmath

Apparently it is kept separate from -static-libgfortran because of licensing issues.

See: https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=745be54bd6634fe63d6be83615e264c83d2ae9f9