It appears that NVIDIA might do what they did with the GTX 1060 with the GTX 1660 Ti, come out with a variant that only has 3GB of VRAM. An ECC leak from the ECC shows that ASUS is planning a few different models with both 6GB and 3GB memory configurations.
ASUS will have GTX 1660 Ti models in the following series DUAL, Expedition, Phoenix, TUF, Turbo and ROG STRIX. It appears there will be 6GB and 3GB versions in all of the series except the ROG STRIX.
NVIDIA is now expected to announce the GTX 1660 Ti graphics cards on February 22nd. We expect to see a large list of custom models available at launch.