Christians under state atheism in the 20th century had to grapple with the same problem. How do you have a religious ceremony when the state sends out a goon squad that beats everyone attending to a pulp and drags half of them off to jail?
Their choice was to continue having them but to do so in secret with very few present which was very brave imho.
But, it's true there certainly are other options. Bear with me for a minute...
In the Bible marriage is the primal human bond of society, the foundation of social life. A marriage is a bond between two people, male and female. The foundational image is that in marriage two become one (Mt 19:5; Mk 10:7–8).
In the creation story, God himself decides that “it is not good that the man should be alone; I will make him a helper fit for him” (Gen 2:18). It is God who brings Eve to Adam after creating her (Gen 2:22), in effect pronouncing the first marriage union in history.
In the New Testament, husband and wife are said to be “joined together” by God (Mt 19:6; Mk 10:9). Jesus attended marriages such as the marriage of Cana in Galilee (Jn 2:1–11).
This image is that of a lifetime bond as stated by Jesus in the form of a command: “What therefore God has joined together, let not man put asunder” (Mt 19:6 RSV; Mk 10:9).
Sometimes the Bible pictures this lifetime marriage bond in the imagery of a covenant. Malachi pictures God as “witness to the covenant between you and the wife of your youth, your companion by covenant” (Mal 2:14 RSV; cf. Ezek 16:8).
What am I driving at? Simple, a correct exegesis of Scripture clearly lays out the status of marriage which is to say what marriage is and what marriage is not. Christian marriage customs arose around that in various times and places.
Christians are free to alter their marriage customs as long as their customs align with a correct exegesis of Scripture with respect to what marriage is and what it is not.
Yes, this can be done in a way that fulfills the requirements in Scripture for Christian marriage while removing Christians in ministry from the path of an increasingly anti-Christian authoritarian state driven by an increasingly deceived, immoral, non-Christian/apostate populace that demands they violate their Christian convictions, adherence to a correct exegesis of Scripture, and free moral conscience (in the context of God's holy normative morality) and participate and facilitate the sacrilege and abomination of homosexual "marriage" or suffer persecution by the state for not doing so.
There is no place in the bible that says Christian ministers need to perform wedding ceremonies... at all. I see a time coming where biblical churches will simply quit performing weddings.