Measuring Distance to find closest point between points from a single table

OK, I took AlBs code and Anonymouss last post and turned it into a measure.  First, I recreated 'Route Information' to have 5 dates' worth of data, one date of which is missing 3 of the locations (Dt is literally just a list of 5 dates 1/14 - 1/18):

Route Information =
UNION (
    CROSSJOIN (
        SUMMARIZE (
            'Table2 (2)',
            'Table2 (2)'[MEMNO],
            'Table2 (2)'[Post Code],
            'Table2 (2)'[Lattitude],
            'Table2 (2)'[Longitude]
        ),
        FILTER ( Dt, Dt[Date] < "1/18/18" )
    ),
    CROSSJOIN (
        SUMMARIZE (
            FILTER (
                'Table2 (2)',
                NOT ( 'Table2 (2)'[MEMNO] IN { "A21200", "A22701", "B10500" } )
            ),
            'Table2 (2)'[MEMNO],
            'Table2 (2)'[Post Code],
            'Table2 (2)'[Lattitude],
            'Table2 (2)'[Longitude]
        ),
        FILTER ( Dt, Dt[Date] = "1/18/18" )
    )
)

Then taking the working code, transformed it into a measure, keeping the Date filter (I'm probably not doing it the most efficient way using variables - I still have trouble getting ALLEXCEPT and KEEPFILTER working without trial and error):

DCH (Miles) =
VAR HouseLatitude = MIN ( 'Route Information'[Lattitude] )
VAR HouseLongitude = MIN ( 'Route Information'[Longitude] )
VAR EarthCircumference = 3959
VAR P = DIVIDE ( PI (), 180 )
VAR House = SELECTEDVALUE ( 'Route Information'[MEMNO] )
VAR __Dt = SELECTEDVALUE ( 'Route Information'[Date] )
RETURN
    MINX (
        FILTER (
            ALL ( 'Route Information' ),
            'Route Information'[MEMNO] <> House
                && 'Route Information'[Date] = __Dt
        ),
        VAR CinemaLatitude = 'Route Information'[Lattitude]
        VAR CinemaLongitude = 'Route Information'[Longitude]
        VAR _DistanceFromCurrentRough =
            80 * SQRT ( POWER ( ( HouseLatitude - CinemaLatitude ), 2 ) +  POWER ( ( HouseLongitude - CinemaLongitude ), 2 )
                )
        RETURN
            IF ( _DistanceFromCurrentRough <> 0, _DistanceFromCurrentRough )
    )

As you can see, on 1/18/18, the distance is different for M49418