TY Baker!
She's making a house call!
>www.dailymail.co.uk/news/article-6736809/Queen-enjoy-secret-dinner-pave-way-state-visit-Donald-Trump.html
The elderly Queen seldom undertakes ‘secret’ dinners of this nature any more and if she were to do so, it would normally be held at one of her own royal residences, namely Buckingham Palace or Windsor Castle.
The fact that she is willing to go to see the ambassador at his own home is a sign of how significant the event is.