I was once in your similiar situation but.
1. I had already taken a 5 day cruise and learn sailing course. I felt confident in my sailing abilities.
2. I was very adventureous and decided that my FIRST trip as "skipper" would be to take my girlfriend for a 25 mile trip up the West coast here in a Martin 22' (BC, Canada)
The winds un-expectadly picked up and I hadn't reefed the sail and we began to take on water into the cabin as the boat heeled over way too much. After much struggle and a couple of injuries I managed to take the sail down in haste, as I then noticed the boat ad no reefing system for the sail.
We tried motoring to our destination but the outboard engine was useless as it didn't generate enough HP to push the hull against the wind and waves. Cold and a little anxious after surges of adrenelline, we motored back to port after only 2 hours out.
My lesson from that: If you're NEW to sailing, even if you technically KNOW how to sail, ... nothing is better than experience, and you should probably learn step-by-step, instead of a huge mouth-full experiences like a huge trip.
If nothing goes wrong and there are no surprises...you'll probably be fine with your plan ( in this case, sticking to the motor )
However, anyone will tell you that in sailing(especially longer distances) there are almost always surprises you didn't anticipate.
If you're going to do this trip I strongly recommend you bring a sailor aboard
Of course, this was my experience, and I strongly encourage being bold and adventureous in sailing! Just not wrecklesness(like not knowing that your sail has no reefing system on it as you headout into potentially dangerous waters, lol)