One tip I've found useful - most TVs have a so-called "Hotel mode" (or a Service mode) where they can have most of their smart features disabled and can be locked to a single HDMI input (e.g. AppleTV / ShieldTV / Chromecast). That makes them into rather dumb panels that usually also disable those ads.

At least I know it's possible on all Sony AndroidTV models and most Samsung models (not sure about their latest Tizen).