In the short term, the answer would be to lift the CRTC's exemption for new media. The CRTC could lift it itself, but, if it doesn't, the Governor in Council has the authority, under sections 7 and 8 of the Broadcasting Act, to issue directions to the CRTC to lift the exemption for new media.
For example, they could say that the regulations apply to companies, even if the latter aren't Canadian. If they have a considerable presence in Canada, that could be enough. Their presence could be defined according to the number of contracts and visits, to the value of payments collected in Canada and to whether they collect data on Canadians. That would be used to determine that they have a considerable presence in Canada. We could then ask them to implement the major objectives of Canada's broadcasting policy.
In the short term, this could be done very quickly, since an order giving a direction is more or less two pages long.