It will come as no surprise that the team that was mentioned was the Ottawa Senators, run by the most frugal owner in the league. The Senators reason was valid due to them not being able to open the building up to its fans compared to the US teams.
It's estimated that the Canadian teams are losing several million dollars in lost revenue every month and even if the Canadian teams played south of the border, they would only recapture a fraction of what they are losing out on.
It's believed the NHL is open to the idea with Commissioner Bettman making threats like moving this summer's NHL Draft from Montreal to a city in the US. This still isn't confirmed to happen or not but if restrictions can't get lifted in Canada, this could definitely have the Canadian teams playing their home games in the US sooner rather then later.