Note that this device is supported by fwupd. To perform firmware upgrades just activate the service
services.fwupd.enable = true;
Then use fwupdmgr to perform updates.
The laptop uses the S2 sleep mode by default instead of S3, which leads to draining a lot of battery during sleep.
See https://wiki.archlinux.org/index.php/Dell_XPS_13_(9300)#Power_Management and https://bugzilla.kernel.org/show_bug.cgi?id=199689#c3 for reference