We present the discovery of 17 double white dwarf (WD) binaries from our ongoing search for extremely low mass (ELM) <0.3M_{sun}_ WDs, objects that form from binary evolution. Gaia parallax provides a new means of target selection that we use to evaluate our original ELM Survey selection criteria. Cross-matching the Gaia and Sloan Digital Sky Survey (SDSS) catalogs, we identify an additional 36 ELM WD candidates with 17<g<19mag and within the 3{sigma} uncertainties of our original color selection. The resulting discoveries imply the ELM Survey sample was 90% complete in the color range -0.4<(g-r)_0_<-0.1mag (approximately 9000K<Teff<22000K). Our observations complete the sample in the SDSS footprint. Two newly discovered binaries, J123950.370-204142.28 and J232208.733+210352.81, have orbital periods of 22.5 and 32 minutes, respectively, and are future Laser Interferometer Space Antenna gravitational-wave sources.