couple of points
Sack Wednesday off. Great day but not worth the thought of leaving the following day (or if you did go home on the Thursday then just sleep until it is time to come back on Friday - Joke)
So if you sack off Wednesday, is there then a chance to come down late on Thursday, say in the evening. Then you have a bit of the night and you are there ready for Friday.
Or - Take the little un with you for a day. drop em back home and come back down
If your wife is just seeing if you would leave the festival, that is a little bit of a weird test.