The next decade will see the arrival of three 30m-class Extremely Large Telescopes (ELTs). These giants are promising profound transformation of our understanding of the universe through large-scale surveys of a myriad of previously unseen astronomical objects across vast areas of sky and cosmic space-time. To carry out such surveys, the ELTs must have i) a super-efficient wide-field corrector (WFC) that can expand their field of view (FOV) over a broad wavelength range and ii) highly multiplexed multi-object spectrographs to target a number of objects simultaneously. The McDonald Observatory (MDO) has a strong heritage not only in designing and building traditional astronomical instruments, but also in developing novel instruments and technologies that are directly scalable to the ELT-class wide field survey sciences. I will highlight some of the scientific opportunities brought forth by the ELT Wide-Field MOS (WfMOS) capability and the MDO’s instrument programs that can enable such capability in the era of ELTs and beyond.