Just wait. The 16/17 models are awful. See the post on the front page of HN right now, about the keyboard repair program. Mine has been in THREE TIMES for sound and keyboard issues. Worst Apple buy ever. YMMV.
Perhaps going for one of the developer Dells with Ubuntu is the safest future bet..
The developer edition laptops aren’t sold in a 15 inch version, which is why I opted to tolerate the Windows factory install. However like other XPS 15 owners, I’ve had a lot of trouble trying to resolve conflicts between Ubuntu and the NVIDIA gpu, which doesn’t seem to be compatible with Canonical’s open source “nouveau” drivers which I think might be enabled by default on 18.04. If you don’t mind the 13 inch display, the developer model might be worth considering in light of the trouble I’ve had trying to seamlessly dual-boot.
I'm used to Dell, and they replace hardware the next business day on location, even when I'm out traveling.