There are only two options:
Conservatives run away en masse from the current GOP party, form a new political movement, and attempt to reach majority status. In theory, it could happen, especially in a three way race..just look at 92..but more likely it would guarantee Dem control of Congress AND the WH....and that'sa scay thought.....or..
Conservatives work to elect a dominant GOP majority, to the extent that the "threats" of GOP moderates, who now, as you so accurately depict, pull the party to the center/left. They can do they, because they know they control the balance of power. If they can't do that, they have no impact, and they'll go along, because it's no fun being on the outside looking in.....That's why Chaffee has clout now, but if the Senate is 53-46-1 GOP..who cares if he goes over to the Dems...and that's precisely why he won't go.... And once we have control, we can begin to work to elect more representatives that accurately reflect the values you espouse...
I prefer the second alternative....