I have the Dell XPS 13 and in contrast to Using Microsoft Designer Keyboard and Mouse with ubuntu 16.04 (on a dell xps 13), it works out-of-the-box! Great. It is a low power bluetooth mouse and keyboard combination.
The issue is that if I do not type for a minute or so (as frequently happens) it appears as if the keyboard or mouse seems as if it needs to reconnect. Am I missing some power saving settings somehere?