We have sailed the Grenadines many times and just booked a 10 day, one way from St. Vincent to Grenada for early January.

Happily, it is not as popular a charter destination as other places and is less crowded. As there are few moorings outside of Bequia and Mustique, we have never had an issue finding a place to anchor. One does not need to be somewhere at 11:00 AM to find a place to spend the evening as is common in some VI anchorages.

Typically, the wind and sea is a bit more brisk than in the BVI at that time of year. There will be a few open ocean passages, but off the wind these are straightforward. Upwind can be a slog. With the experience you describe I do not think you will have any problems.

We typically fly to St. Vincent via Barbados. If you do this, I recommend spending a few extra bucks and use SVG Air from Barbados as opposed to Liat. From Grenada there is jet service to the US (Miami for sure).

We have spent overnights on St. Vincent at Keartons and Blue Lagoon with no issues, and enjoyed very good dinners at both places.

Feel free to PM if you have particular questions.