If you insist upon talking TLS 1.3 draft 23, which is the last substantive change before the draft went to the RFC queue, google.com is perfectly happy to talk TLS 1.3 draft 23.
TLS 1.3 has downgrade detection, so if a middlebox tries to downgrade you (e.g. to TLS 1.2) without proxying the entire connection the TLS 1.3 implementation in your client will spot that and reject the connection.
Proxying is possible (including with a downgrade) if you trust the proxy. So, don't.
If you have a recent-ish version of Chrome or Firefox you are already using all this.
TLS 1.3 has downgrade detection, so if a middlebox tries to downgrade you (e.g. to TLS 1.2) without proxying the entire connection the TLS 1.3 implementation in your client will spot that and reject the connection.
Proxying is possible (including with a downgrade) if you trust the proxy. So, don't.
If you have a recent-ish version of Chrome or Firefox you are already using all this.