I believe (could be wrong) couples may marry without a priest if none can be had for over two months, to prevent concupisence, or if extenuating conditions exist, exactly like financial, legal, care of children, basic needs like food, clothing, shelter. In the case I heard about, the couple had purchased a house after being engaged for three years. They had both not signed a lease for the next calendar year, in the belief that they had a priest. At the last week, their county was locked down, making it impossible for the priest to come, they both had to be out of their rentals, and to complicate even more, the man has full custody of his special needs son with a woman to whom he was never married from his pre-conversion days. These were older people, in their late 40s, who had nowhere to go, iow, the man and son, at least, would be homeless. Rather than risking moving in together they did their own marriage.