Seems to me the remedy is already built into the constitution…. It’s called the “States”. These “States” have a functioning government “in some cases” and are completely capable of handling such a situation. If anything the states could temporarily appoint someone if necessary, I believe this would be constitutional as it originated from the state. Appointed by the Governor, state legislature or snap election would be up to the states to determine. If the Congress is able to start passing constitutional amendments at will without major pushback then our entire government is captured.