Ted Cruz is an odd case, before 2018 he was a textbook Evangelical traditionalist neocon but then he became sorta "based" and started to distance himself from the old "fundie neocon" GOP playbook. I still think he's religiously devout but I also think a lot of his earlier stances were more performative so he could stay in the good graces of the Evangelical neocon establishment in the GOP at the time.
Plus, Ted Cruz is a Generation X'er as opposed to a Baby Boomer. I've noticed there are some subtle differences between Gen X fundies like Cruz and Boomer fundies like Pence or Sessions, and I doubt Cruz will want a return to the Satanic Panic or any of the hardliner redneck neocon stuff. As for marijuana reform, I could see Cruz personally opposing it but also not interfering in any attempts at legalization at state or federal levels.
If Trump can win 2020, I think we will definitely see the start of a Seventh Party realignment and I also the GOP's best chance for 2024 in that scenario would honestly be Kanye West with Ted Cruz as his VP.
Kanye's got the star power and if he does end up being a real Perot/Nader style spoiler for 2020 then he's shown he's got the ability to get the votes if he's with a major party. Ted Cruz has been in the Senate and he knows how the game is played in Washington but he's also young enough to not be an elderly geezer by the time 2024 rolls around unlike most of the Boomers who are in Congress, and can probably serve as a more reassuring and grounded backer to help keep Kanye from going too far off the deep end.
This may sound like wishful thinking, but I could see Ted Cruz backing a second more serious Kanye West run because they're both religiously devout