Alberta

I don't like the man any more than you do, but let's not forget that the Canadian Charter of Rights and Freedoms explicitly protects freedom of association: the freedom to gather in groups for a collective purpose.

Of note is that the actual activities are not considered in this section. Other laws can protect or prohibit the activities themselves and possibly even support conspiracy charges if the gathering is expressly organized to plan illegal activities.

Carlson is not a Canadian citizen or resident. Presumably he must declare his purpose for entering Canada, but I don't think that giving a speech is legitimate cause for exclusion.

My opinion is that the appropriate response is to organize groups of people to legally attend whatever events are hosted and to mount protests and opposing events. In a perfect world, the majority of space open to the public would be filled with those who oppose his ideology and message.