Section 2 (2) of the Compulsory Automobile Insurance Act (CAIA) states:
For the purposes of subsection (1), where a permit for a motor vehicle has been issued under subsection 7 (7) of the Highway Traffic Act, "contract of automobile insurance", with respect to that motor vehicle, means a contract of automobile insurance made with an insurer.
Section 7(7) of the Ontario Highway Traffic Act states:
The Ministry may issue a permit of any prescribed class, number plates and evidence of validation to any person who meets the requirements of this Act and the regulations.
The definition of "insurer" under the CAIA states:
"insurer" means an insurer licensed under the Insurance Act and carrying on the business of automobile insurance, but does not include an insurer whose licence is limited to contracts of reinsurance
Therefore if you have a vehicle with an Ontario registration that vehicle must be insured with an insurer licensed under the Ontario Insurance Act (OIA). As Progressive Insurance is not registered under the OIA you are in violation of the CAIA. Either register the vehicle in Florida or insure the vehicle with an Ontario insurer before that vehicle sets foot in Ontario.