Warranty on Replaced Parts

I bought a Dell XPS 15Z in the USA and I am pleased with it.

I am currently travelling abroad and the laptop is in warranty.  The ethernet port has been diagnosed as faulty by Dell Chat and my 15Z requires a new motherboard.  Since I brought this issue to Dell's attention within the warranty period, Dell has agreed to replace the motherboard under warranty - but after the warranty expiry date - when I return to the USA.

My question is this:  what warranty will I get with the new motherboard?  It would seem unreasonable for me to be expected to pay for a third motherboard if the replacement motherboard (#2) packs in after a short period.