And then there is Sheep It Render Farm. You donate render power when you don’t need your PC. Earn points for that. Then consume those point when you utilize 20++ parallel render pipelines from other peoples PCs when you want to render your stuff.
A mid-tier GPU is more than enough if you're willing to wait a bit more on render times. You can always optimize the scene to lower rendering times. This video is 1800 frames. Depending whether it was rendered with Eevee or Cycles, it can take anywhere from a few hours up to a day or more to render the whole animation by using a single mid-high end GPU like a 3060 or 3070.
https://www.sheepit-renderfarm.com/home