How long can your high last on 4mmc if you keep redosing?

I was planning on taking 150mg orally at first and then 50mg bumps throughout the rest of the night, until I've finished 500mg.

Will I still feel "good" after 4 hours or so? Im aiming for a good 8 hour run, maybe 9.

The issue is that im hosting a pregame before the rave and i have tons of anxiety about it. Id like to be decently high before my friends arrive at 9pm. We leave to the rave at 11:30pm. We will stay until 5 or 6am. What are your recommendations? Should I just suck it up and take some orally at 11:30? My friends are on MDMA but they arent dropping until 11:30pm. I know MDMA only lasts 3 to 4 hours, maybe 5 or 6 if you redose.

Thoughts?