BT Whole Home - not in daisy chain?

[SJHPS24]

I too have the scenario where I want to get wifi into an outbuilding and I would be interested to know if you cracked the challenge.  Power line extenders have proved not to work for me because of different circuits.  So my set up is that my router in the study interconnects to a black BT disc in the lounge via wifi.  I have an CAT 6 ethernet cable which already runs from the outbuilding to the area where the disc is in the lounge.  I can't get a cable to run straight to my router.  So the simple and fundamental question remains - if I got a second disc, can I use the ethernet cable to physically connect the two discs together and would that give me an extended network into the outbuilding?  I'm not after a high data rate solution and it's not a long disc chain I'm trying to create, almost just a point to point.

Appreciate your thoughts

[licquorice]

 As far as I'm aware, the Ethernet port on the disc can only be used as an output rather than as an input.

Why not simply connect the disc to a cheap WAP (wireless access point) rather than another disc.

[naylor2006]

The BT Complete Discs (Black) (Wholehome is White) can indeed use Ethernet as a backhaul in the same way as Wholehome (Non Premium), so you could connect multi discs via ethernet back to the router...separately. 

Problem is this isnt your use case, you want to connect two discs together, neither disc has an ethernet route back to the router relying on WIFI instead so the discs themselves would likely get confused by thinking each other was the 'source'. I dont think it would work likely stopping both discs from working.

@licquorice has suggested a perfectly good option however.