We currently want to start hosting all our assets through AWS S3 and we also want to server everything over https. I understand I can use the Amazon Certificate Manager (ACM
In AWS API Gateway, you can create a proxy resource /{proxy+} that maps to s3-website.
Be sure to map not to s3 alone, but s3-website, so you get PATH/TO/DIR/index.html returned for PATH/TO/DIR, and possibly other things working as desired.
API Gateway is served over HTTPS, optionally under your own domain.
This is not very good option though, because you have to manually add all allowed HTTP return codes, and there's a limit of 10MB payload in a request, as this service is aimed at REST APIs.