Today, I-95 goes from Boston to Miami, I-5 goes from Vancouver to San Diego, and I-75 is only missing Knoxville to be complete from Detroit to Miami. That's 3 N-S routes!
After the initial Elon Mystery Tour as an E-W route, Tesla completed the I-15 route from SoCal to I-70 to help a little. The I-70 path across the midwest seems to be taking forever, the I-90 connection out of the Pacific NW got stalled in Idaho and Wyoming, and I-40 is finally getting started towards OKC. I-80 from the Bay Area to SLC is the only bright spot for recent E-W route construction.
Looking at this, I think that the N-S routes are a little ahead of the E-W routes.
Trinidad it the first of three Superchargers this year (also Pueblo, CO and Las Vegas, NM) to connect Denver to Albuquerque on I-25. Even with Cheyenne, WY, this section of I-25 is a pretty short N-S route.