Personally, I prefer to manage my own DHCP/DNS using the actual dnsmasq package. This requires that you configure the dhcp pool for your bridge and then create static dhcp entries for the containers you want,as per below example:
dhcp-range=lxdbr0,10.0.0.1,10.0.0.253,12h
dhcp-host=container1,10.0.0.1
dhcp-host=container2,10.0.0.2
dhcp-host=container3,10.0.0.3
The nice thing is that it will still create DNS entries for these machines from the host, which you can provide downstream.