Reddit mentions of StarTech.com 30 ft DisplayPort 1.2 Cable with Latches - Active - 2560×1600 - DPCP & HDCP - Male to Male DP Video Monitor Cable (DISPL10MA)

I have successfully used the following 3' and 10' passive DisplayPort extensions:

StarTech.com 3 ft / 91 cm 20 pin DP DisplayPort Extension Panel Mount Cable - DisplayPort to DisplayPort - Male to Female:

https://www.amazon.com/gp/product/B003YKX6JK

Cable Matters DisplayPort to DisplayPort Extension Cable (DP to DP Extension Cable) 10 Feet

https://www.amazon.com/gp/product/B00L1K1KDE

Note: I have occasionally observed static/sparkles in the video feed when using the 10 foot extension. Since the Rift S cable is 16 feet, adding another 10 feet seems to be on the verge of the limit for what we can do with passive extensions.

The following did NOT work:

StarTech.com DisplayPort Cable - 30 ft / 10m - Active - 4K DisplayPort to DisplayPort Cable - DP Cable - Active DisplayPort Cable

https://www.amazon.com/gp/product/B00IFZN2O8

I connected this directly between my 1080ti and the Rift S. I had to use a female-female DP adapter.

The Oculus software showed the DP was connected, but the screen was totally blank/dead - nothing at all.

I did test the 30' active extension and female-female adapter with a 1080p LCD monitor and it was working fine, but no go for the Rift S. Either it can't handle the bandwidth, or something about this cable (perhaps the fact that is a unidirectional cable) prevents it from working it with the Rift S.

The StarTech was the only active DisplayPort extension I could find -- if anybody has experience with any others, please comment!

I don't think you even need a thunderbolt dock. Get two long DisplayPort cables (or 1 if your monitors can be daisy chained) and then a USB extension with a USB hub on the end. Plug your mouse and keyboard into the hub and plug any audio devices into your monitor. (I assume that they have audio, considering they are high end monitors)

Edit: Because I have nothing else to do, I looked into a single cable thunderbolt solution.
The idea came from this video, and it will be extremely expensive. Like is there really a good reason to not just move the PC by your monitors?
First, to use Thunderbolt, you need to actually have Thunderbolt on your computer. Luckily for you, ASUS has a PCI card to do just that. Your motherboard is not listed as supported, but your motherboard does have the Thunderbolt header that is needed by the card, and is a newer mobo from the same manufacturer, so there is a possibility it might work. Assuming it does, you would just connect the DisplayPort from your GTX 1080 to the Thunderbolt card.

The next thing you need is a long Thunderbolt cable. I don't know how far away the computer is going to be from the TB dock, but here is a 33' long Thunderbolt cable. If you need longer, you can get 100' for $600.

Next, you'll need the Thunderbolt dock. There are many out there. I have no experience with any of them Belkin and Elgato both make them.
An unfortunate thing about the Thunderbolt docks is that they only support dual display when one of the displays is a Thunderbolt display. Otherwise, you can only use one over HDMI or one over MiniDP to DP, but not both. So that would mean repeating the whole setup with 2 docks, or just going with the suggestion I made above.

The alternative is to spend quite a bit more on an active cable https://www.amazon.com/DisplayPort-Cable-30-10m-Active/dp/B00IFZN2O8/ref=sr_1_1?ie=UTF8&qid=1503881528&sr=8-1&keywords=active+displayport+cable+-dvi+-hdmi

Zoop

5m cable is probably a lot cheaper, you would still need to add money, I'm pretty sure. ( 10m would need to be active )

Check these prices for instance
https://www.amazon.com/DisplayPort-Cable-30-10m-Active/dp/B00IFZN2O8