“I actually had to run to make it. I just barely made it getting to my connecting flight, but thank God I did,” Johnson said. “I keep checking my email to make sure my flight [back] isn’t cancelled … But if it does, hopefully we get something booked.”

The trade group Airlines for America said more than 3.5 million people have experienced delays or cancellations since the shutdown began, adding that the ongoing situation is “not sustainable.”

Airlines shared tips with people preparing to travel ahead of this holiday season, advising that travelers be prepared, watch the status of their flight, and act ahead of time when possible.

Simon Peter Groebner of the Minnesota Star Tribune contributed to this story.