Your anus can’t feel temperature that much so cold water hitting it really isn’t that big of a deal.
Warm water bidets don’t use electricity, they use a hot water tap from the near by (and generally easily accessible) bathroom sink. Sure you might need to drill a hole in a cabinet but it’s not outrageously inaccessible or expensive to setup. You just need to watch like 2 plumbing youtube videos.
I live in the US. I am not rich. I have a bidet—it is a hand nozzle attached to my toilet’s water tap that cost $30.