Mr. Kilgore estimated that it would cost $50 million to replace his Huawei equipment. If that is the only option, he said, he might have to shut down the company, leaving his customers without wireless service.

Mr. Rasmussen said that would be a big blow to his farming operation.

“We’re getting squeezed on all sides,” he said. “The tariffs and trade affect our prices, and now this could affect our ability to farm.”

Mr. Kilgore has argued, through his work with the Rural Wireless Association, for an exemption to the F.C.C. rule for small rural carriers, or for subsidies to replace the Huawei equipment. A bipartisan group senators recently introduced a bill that would set aside about $700 million in grants to carriers forced to rip Huawei equipment from their networks.

Mr. Kilgore got another glimmer of hope, too. On Monday, he got an email saying Brendan Carr, an F.C.C. commissioner, was heading out to Montana. They will get together in the next week.

“This is a big day,” Mr. Kilgore said after getting the email. “It’s not every day someone from Washington comes to visit.”