Thank you dear folks for all the feedback, I'm weighing up all suggestions and may try photoing myself with a slightly higher hemline, also with a belt. I'm debating lowering the neckline a cm or two as well, or reshaping it a bit more boat-like.
Ironically After watching the news tonight our plans may change and we may not go over after all. You can probably guess why - the Coronavirus situation is clearly escalating rapidly and the last thing we want is to be quarantined away from home and in another country. There will be airports, plane journeys and large gatherings and we are both risk averse but keen to see our respective families. We said we'd decide by Thursday.
But I'll finish the dress this week anyway and, if necessary, it can keep for the next "big occasion".