gengar

First off, Orange County (John Wayne) airport is SNA, not SAN (which is San Diego airport).

The primary issue is whether VS will interline baggage to DL on separate tickets - can someone who knows VS policy please comment on that? DL's official policy is to interline to VS on separate tickets since they are partners, but I don't know the reverse.

If VS interlines baggage to DL on separate tickets, then all OP has to do is pick up checked bags at LAS, clear customs, and drop them off at the bag drop. OP can then clear security at T3 and proceed to the DL flight in Concourse D. Three hours is plenty of time.

If VS doesn't interline, it's a huge hassle because OP will be kicked out of customs at T3 and have to lug bags to T1 (where DL does ground handling) and it is very inconvenient to change terminals at LAS. There is a long distance between terminals, and the shuttle is slow and runs inconsistently. OP would be forced to do this if taking WN, as WN also does ground handling at T1 and it is not possible to interline with WN. DL's checked baggage cutoff for domestic flights is 45 minutes so this is still a very make-able scenario, but adding at least ~20mins for the terminal transfer really narrows the margin of error.

LAS has Global Entry. A full list of US airports with Global Entry can be found here: https://www.cbp.gov/travel/trusted-t...ntry/locations

I have GE and it has never taken me more than few minutes to clear immigration/customs at LAS.

It's a 4 hour drive even with absolutely no traffic. Also, a one-way rental from LAS to SNA will likely be $100+, then add gas. It's much less convenient and economical than a $58 flight IMO.