Welcome to the community and thanks for posting! https://help.netflix.com/en/node/87 Take a look. Just remember it can take 8 hours before this change goes into effect. I've seen it change for me within minutes but just an FYI. Also this change will be across multiple platforms. Hope this helps.
Amazon Prime will eat your lunch. Generally not good to stream from any site that doesn't allow setting the definition, never know how much will be used. I believe even their SD is higher usage than Netflix, Hulu or YouTube.