The laws regulating dogs exist for a good reason.
If you think there should be an off leash park, lobby to get the relevant laws changed.

I have to obey the laws ... and so do you!

I carry pepper spray and will spray your off leash dog if it gets within range.  If spray is not practical I will kick your dog away, or fend it off with a hiking pole.

I do not have to accept the risk of dogbite injury or of being knocked down by your unlawfully at-large dog,  and you probably don't have enough money to pay my damages if I am injured.

Google "dog bite injuries in Ontario" and the first half-dozen results will likely be lawyers advertising to represent dog-bite victims.