Installing Ubuntu on a Dell XPS 13 9350
Get the latest kernel
mkdir kernel45
cd kernel45
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.5-wily/linux-headers-4.5.0-040500_4.5.0-040500.201603140130_all.deb
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.5-wily/linux-headers-4.5.0-040500-generic_4.5.0-040500.201603140130_amd64.deb
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.5-wily/linux-image-4.5.0-040500-generic_4.5.0-040500.201603140130_amd64.deb
Install them and reboot
sudo dpkg -i linux-headers-4.5*.deb linux-image-4.5*.deb
sudo reboot
Wireless:
wget http://en.community.dell.com/cfs-file/__key/telligent-evolution-components-attachments/00-4613-01-00-20-84-05-08/brcmfmac4350_2D00_pcie.zip
unzip brcmfmac4350_2D00_pcie.zip
sudo mv brcmfmac4350-pcie.bin /lib/firmware/brcm/
sudo chmod 600 /lib/firmware/brcm/brcmfmac4350-pcie.bin
VPN
sudo apt-get install network-manager-openconnect
Power management
sudo apt-get install tlp tlp-rdw smartmontools ethtool
sudo tlp start
Configure as per the docs.
Also, check out Ubuntu power saving tweaks