My son, who is in his early 20s, just came home after spending 11 days working in Monte Carlo, Monaco.

Before his return flight he had to take a COVID test at the Nice, France airport, and we were worrying what would happen if he tested positive. Like you said, the cost of a lengthy hotel stay and a rebooked flight would cost many thousands of dollars.

Luckily, he tested negative but that risk should be considered for any traveling to Europe right now..