For my own networks, I’ve been using IPv6 subnets for years now, and have NAT64 translation for when they need to access Legacy IP (aka IPv4) resources on the public Internet.
Between your two options, I’m more inclined to recommend the second solution, because although it requires renumbering existing containers to the new subnet, you would still have one subnet for all your containers, but it’s bigger now. Whereas the first solution would either: A) preclude containers on the first bridge from directly talking to containers on the second bridge, or B) you would have to enable some sort of awful NAT44 translation to make the two work together.
So if IPv6 and its massive, essentially-unlimited ULA subnets are not an option, then I’d still go with the second solution, which is a bigger-but-still-singular subnet.
Weather station, terrestrial/satellite TV DVR (TVHeadend), Git repository (Forgejo for a nice web UI, cgit for a classic UI), DNS resolver.