If you really need it to be secure and private, and are communicating mostly with known acquaintances within a reasonable radius, with low bandwidth requirements, LoRA with encryption is the best bet.
It is a higher bar of entry but at least you can be confident your messages won’t be intercepted in any useful form.
While you should do this to block your TVs telemetry and other undesirable behavior, realize that YouTube native TV app ads can’t be blocked at DNS level alone without also blocking the core functionality of YouTube, due to the way it serves the ads.