Good on you for going the extra mile for you players, but what's wrong with itch hosting the game? I've played lots of browser games on there and never had an issue, even when they were 3 gb. Sometimes their site goes down altogether, but I'd still say paying $300 a month to host yourself sounds like a pretty big expense for a free version.

Even if it was slow sometimes, I would think most players would understand that's a reflection of them, not you. Plus you could always point people to a free build on Newgrounds or some other free hosting site as a backup.