I'd go for 1, with 2 a close second, and 4 being acceptable. That long flight followed by a 25 hour drive doesn't sound like fun.

bzcat's summary is pretty complete, but I'll add that the walk to DL or UA from TBIT isn't likely to be bad at all, and might even be a nice opportunity to stretch your legs after a long flight. The sidewalks haven't been crowded at LAX throughout the pandemic, so two people rolling through with two carts should be pretty relaxed. I've flown in and out of LAX a number of times through all this and have yet to get on a shuttle. I walk to the LAXit lot or QuikPark (just off airport) from T6, and it's been fine. You won't even have to worry about the off chance of rain, since you aren't crossing the U or going off airport.