The last time I activated a TV was in 2022. It was a Sony X85K and it didn’t require a connection. I’ve subsequently only used it with a CCwGTV.
Before that I activated a Samsung U…7300 or something like that in 2020. That didn’t require connection either. I also used it with a CCwGTV.
The VPN should keep access to the homelab even when the external IP changes. Assuming the VPN connects from the homelab to the cloud. The reverse proxy would use the VPN local IPs to connect to services.