One of the biggest road blocks every year for NHL GM's to make big blockbuster deals at the deadline, is the no trade/movement clause. 

Players sometimes either have a full no trade/movement clause where they can reject any trade while some players have modified ones where they can usually block trades to about 7-8 teams. 

The Athletic recently got together with a couple of player agents for a poll and one of the questions was "Which two teams are most likely to land on a client's no-trade clause"?

Two teams pretty much ran away with it as Winnipeg and Ottawa sit at the top of the list with only one vote separating the two. 

For Winnipeg, it's mostly a location thing as Winnipeg has arguably the coldest winters of any NHL team.

For Ottawa, it's an ownership thing as according to agents as long as Eugene Melnyk owns the Senators, nobody will want to play there. 

The Edmonton Oilers came in third, however agents point out that the opportunity to play with Connor McDavid and Leon Draisaitl is starting to overrule the cities cold weather.

Montreal also had a brief appearance and a couple of agents had this to say:

"Montreal, because it’s just so hard to play there. You win two in a row, they’re planning a parade. They lose two in a row and the whole city is on suicide watch.”

“Montreal because of taxes. It’s pretty bad.”

Here's the full list:

Source: The Athletic