Certainly areas of agreement and disagreement. The utility markets are a mixture of regulated prices (rates) and competitive prices. I suspect that the wind turbines were built not just to serve your area of Ontario but instead were built to be part of a regional or national plan of clean energy grid development. Therefore, it is likely that more were built than locally needed and transmission capacity and substations were built to meet the larger capacity and larger market, not just your local needs.
Unfortunately, it also is likely that some of the larger market (sales to the US, for example) is competitive and your local market is not competitive, with the result being that regulators have shifted to the local market fixed costs (turbines, transmission lines, substations) that cannot be recovered in the competitive market.
I don't agree that "the lines are always carrying power so really no difference whether they're used or not." The question is how much power, not that they always are carrying power. They need to carry enough power to meet peak demands in a service territory. Defining the territory is an issue. Determining who is consuming the most power is an issue. As mentioned above, if everyone only needed a small peak load, it would be easy to plan the system. But if some have erratic and large peak loads, then capacity needs to be provided to meet that need. And in my opinion, it is the larger, peak load customers that need the more expensive transmission capacity, and they should pay a larger share of the fixed costs as compared to a small user. Therefore, fixed costs should be variable based on the peak load needs of the customer.
I understand your plight. I would gripe too in your situation. I face a similar situation as our local utility keeps raising the base rate (fixed charge). My efforts of conservation (and also my own solar PV system) have greatly reduced my kWh usage, but my bill has gone down little due to increases in the base rate. I have no objection to a "fair and reasonable" base rate, but I would argue that the "fair and reasonable" base rate needs to be variable and increase according to the peak demand of the customers. How to measure and do that may be complicated, but a simple flat charge regardless of usage is not fair and reasonable.