I agree with you. I would not drive 6+ hours for a measly 24 hour "relax" time. I also would not let my wife(or anyone else) with such little experience drive that big of a combination. As has been said, there is just too many things that could go wrong.
I would either take the trailer there on Friday night, or skip the trip and tell the friends that it is too long of a drive for such a short visit. The friends seem a little selfish to me by not wanting you to arrive ahead of them, especially when it is only a 30 minute drive for them. They could drive there on Friday night and watch you park the trailer, and then come back on Saturday if that is their worry.
