I aim to keep running and drinking fluids till I get an official offer from HR then stop exercise till after pissing.
Also, I believe that you should probably stop running a few days before a test because THC is fat stored and the burning of fat will burn it. I could be wrong about this though.
If the first mornings void had been showing a positive, and the scheduled test is 3 days (or less) away, then all fat-burning activities should be curtailed and the body should revert to "storage mode" - be as dormant as possible - until after the U/A. That way the donor wouldnt be releasing a bunch of THCA into the bloodstream, which would end up in the urine to be detected.

If youre consistently testing negative with the first-mornings void (regardless of line intensity), youre good to go. No need for any dilution. Just drink enough fluids to where youre able to produce a sufficient volume of urine sample at the collection facility.

Also, drinking fluids is only helpful on the day of the U/A. Drinking a bunch of fluids in the days before the U/A is of no help. To find out why, utilize the Forum Search button with the terms "drinking water useless kidneys rate".