I did have my motor on board, for the exact reasons you mention.
I was just determined not to use it, unless I really needed it.
I don't think I needed it in this case. I think I should have done things differently. I'm thinking maybe the anchor idea. Except instead of walking it out in chest deep water, I should have dropped it while sailing into the beach the night before.
I could drop the anchor off my stern, maybe 50 ft out from the beach, pay it out as I sail in.
Then kedge off backwards, transfer the anchor from stern cleat to bow cleat. Set sail, and already be sailing when I pull up the anchor. Might work pretty well. Still, I can imagine ways this could go wrong.
I am curious to hear of ideas others have to improve my system.
Actually that's what I was going to propose as a possible method. It would leave you bow-onshore at closest approach, so your rudder would have more water.
And yes, much could go wrong, and in ways neither you nor I would necessarily predict. And in general, getting close to a beach that's a lee shore, is asking for (or at least flirting with) trouble. But in light winds, it could be okay. while well offshore, round up and drop your main, then approach the beach jib-only with anchor dropped from the stern when the time is right, since it's easy to douse the jib even when downwind. Pray (in advance, and at the time too) that the anchor digs in immediately and solidly.
I'm assuming a sloop rig. If you're main-only, then same approach, but drag the anchor of the stern as you approach the beach, to keep your bow downwind while you are "bare poles" (pole)
Also pray that the light onshore wind doesn't increase. And don't tell your underwriters, they will tell you to go the the beach by car instead.