Just came across this thread. Old but updating..
The miniature DPAs are two wire mics. The DPA cable is coaxial, with a very thin signal wire that is rather difficult to solder, a braided shield ground, and aramid tensile reinforcement strands.
I use this source for microdot extension cables of whatever length I want-
https://www.cdint.com/catalog/category/CablesThere are cheaper sources of cable, but those folks supply cables of whatever length you want terminated with male or female microdots. If I need a pair with different connectors on the opposite end I order a cable twice the length I need, cut it in half and reterminate the cut ends myself. The RG174 cable thicker than the DPA cables, but not overly large in diameter, and features a center conductor that is easy to solder. I use the the "flexible" version which features jacket that is "rubberier", but would also consider the "low noise" version of the cable. For multiple channels combine I run a bundle of however many run of this I need in a single Techflex sheath. That retains good flexibilty even with bundles of 8 channels or more, forming a snake about the diameter of a finger.
For single-wire multichannel runs, typical balanced mic cable will accommodate a stereo pair (shared shield/ground), as will multi-conductor cable for higher channel counts. I've used some Mogomi multi-conductor cable for that which is super small in diameter, similar to a single run of RG174.