Get Leica Q at B&H Photo.
Dynamic range looks promising—the Q looks to have an improved version of the Leica M Typ 240 sensor. Could an improved M240 with more features be on the way or some other interchangeable-lens M with built-in EVF and a new autofocus lens line? I would not rule it out, though Leica is slow to move on the M platform.
See graph from RawDigger below (highly recommended tool for any photographer for ETTR evaluation and more)—with a black level of 512 and values out to nearly 16K, the full bit range is utilized. How much usable dynamic range is there is not given by bits of course, but this is no 12 bit file.
The Leica Q files are uncompressed at 43.1 megabytes each, so these are 14-bit files (14 bits / 8 bits * 24 megapixels = ~42 megabytes + a bit of other stuff). Regrettably Leica offers no lossless compressed format in the Q (as is done on the M), which would on average cut the file size down to 25MB or so with absolutely no change to the data (lossless).