Quite sure at some point or other we all have setup a scene that takes serious strain on your PC. i know i have many times, and i usually resort to using blenders render from command prompt option.
Today i found this ....https://www.sheepit-renderfarm.com/
an online blender community renderfarm.
Haven't tried this as yet because i dont have anything to render at the moment, but it certainly does look promising and i will be giving it a go.