There were some thoughts about making EspruinoHub work with multiple hubs, so presence got tweaked depending on whether a device could be see by any of the hubs. I guess you could still do this with manually node-red - you'd just have to handle looking at both 'presence' variables.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
There's not a great deal I can suggest...
You could use an external bluetooth dongle that has greater range - for example https://shop.espruino.com/usb-bluetooth
There were some thoughts about making EspruinoHub work with multiple hubs, so presence got tweaked depending on whether a device could be see by any of the hubs. I guess you could still do this with manually node-red - you'd just have to handle looking at both 'presence' variables.