I am using a sonoff ZBBridge flashed with Tasmota as a nice zigbee dongle, works very well and allows me a good central location. However I would like to use zigbee devices in a small building in my garden that is outside zigbee range (by some way). It has IP connectivity so ideally I would just add another ZBBridge to that building and control all from a single Home Assistant instance. However I see you can only add one zigbee integration. Is it possible to get this setup to work?
I don’t think so. You could use zigbee2mqtt to create a second zigbee network, but zigbee2mqtt does not work with the Sonoff ZbBridge. A CC2530 connected to a ESP could be a replacement.
I was using ZHA with the sonoff device which is zigbee support in HA. For the 2nd (and soon 3rd) device I use ZigBee2Tasmota which sends MQTT commands to HA.