It's perfectly possible and probably won't add much complexity or significant cost. I have no experience, however, in configuring ELB with HTTPS - usually I just go with the known quantity of a local nginx.
Using ELB(yes, even for one machine) from the start means one less process to worry about, you get HTTPS and don't have to deal with certs, its also cheap.
Since he's striving for "simplicity" and already is in AWS.
I feel it is one more thing to worry about as I now have a dependency on something that I can't run locally nor control. It is also more expensive and locked in.
For someone with experience setting up nginx with https from letsencrypt is the same complexity as a hello world. Same thing for running redis yourself instead of adding a cloud provider.
