"When everyone is super, no one will be." -Syndrom
The problem with extending the HC season is that it gets more accessible for everyone to achieve all the rewards. The leaderboards (I don't care for them myself, but I know folks do) lose value the longer the season lasts. The cosmetics lose their shiny luster if the first-place prizes are given to everyone.
One way to extend a season (let's say - six months) while not diminishing the rewards is to have the rewards unique to classes (or races, but meh). Make each class's 1750f, 5000f, 10r, and 20r rewards unique to that class. The class could be determined similarly to a TR's past life (the highest or first highest class). Leaderboards might get reduced to the top 20 in each class.
For SSG, there would be a wealth of potential game-balancing data. Only one person made 5000f and 20r with a rogue? That might mean rogues could use a little more love. I'm not hating rogues here - it's an example of a class I consider to be difficult. That's kind of the point. On a regular server, your rogue puts on their 5000f rogue cloak riding a 20r rogue mount; you know that's going to be the best pirate you've ever seen.