You're not right about Lubbock. Tech has more fans there. (I live in Lubbock). Nonetheless, UT always brought an army with them. They always bought their ticket allotment. And they bought up as many "single" game tickets as they could. (There were never very many to be had) They'd pay a premium for whatever seats were on the resale sights. On top of that (and this is NO exaggeration) UT always brought at least 10,000 fans who knew they weren't going to get into the game. The parking lots around the stadium were filled with burnt orange fans watching the game on big screens in pick up beds or next to million dollar RV's etc. The bars were packed in every part of the city, the restaurants were packed and the hotels were charging triple rate with a two night minimum. I would dare say that the financial impact in Lubbock of the UT game every other year was $50,000,000. The A&M game in Lubbock was nearly as good and the OU game wasn't far behind.
BYU will indeed have a lot of fans at all away games. Tech probably will be the second best traveling fan base. Colorado is looking forward to having visiting fans again. The west of the rockies schools didn't travel to Boulder. KST, KU, OSU & Tech always sold out their allotment in Boulder. (As did Nebraska, OU & UT). All is not lost here in Lubbock, we have replaced the UT home game with the mighty Bearcats of Cincinnati and replaced the Oklahoma Sooners with the Arizona State Sundevils. So the economic impact loss prolly won't be more than $80-$90 million.