Quick help please - stripped wheel nut.

+1. Everything David said will do the job.

And for the thread lock, did you use red or blue?????

Never RED, always go BLUE

[VintageMA]

No worries - blue on the threadlock, maybe just too much of it - and the HPI nuts have that wheel lock ribbing on the inside edge.

[BL_RV0]

I cut one in half with a dremel once, worked, but only use it as a last resort.