Ultraportable laptop suggestions [$1000-2k] - buy now/ wait?

I am just returning my Dell XPS 13 due to some issues that I experienced while using this laptop. I am now stuck with an old HP bricktop which I put Linux Mint on to breathe some life into, still it is painful since it has an old Celeron CPU and 2 only gigs of RAM.

I am looking for a replacement to the XPS 13. I might even get the XPS 13 again, if it goes on sale again, since I really liked the laptop. But Dell's customer support is a bit of a let down for me. Otherwise the XPS 13 is just the right laptop for me- I need something as/ more compact with the same choice of IO (2x USB 3.0, TB3, SD card reader).

I am considering the entry level Surface Book and the 256 GB SSD variant 2015 retina MBP. What is annoying is the storage in the Surface Book, as I am planning to dual boot with a Linux distribution. Windows 10 and other preinstalled Windows software eats up a good ~40-45 GB on it's own. And both doesn't have a Thunderbolt 3 port for possible future eGPU expansion. I played around with the Surface Pro (not book) and I really dislike the shallow keyboard. The 256 GB SSD model only comes with a dedicated graphics card, so also a sharp increase in price.

Also, the MacBook Pro seems to be getting a design refresh, and if rumors are true it will only feature USB-C ports, much like the new MacBook. Will the price of 2015 MBP decrease when the new one comes out? I am planning to wait for the refresh anyway, at least we get a confirmation of design from Apple.

I would really appreciate any recommendations. Also, what would be a good time to buy laptops/ when are there a most discounts? I won't mind waiting till the end of this year. I need a 13-15" ultra portable laptop with a good choice of I/O and decant specs.

Thanks in advance.