Scrlttr2 - moving the date from below both the addressee and the from address, to between the two

The default sclttr2 behaviour is to format like so:

RIGHT_ALIGNED(date)

I want to change that to:

RIGHT_ALIGNED(date)

with sensible gaps between them. I am using

\documentclass[
fontsize=11pt,
paper=a4,
parskip=full,
enlargefirstpage=off,
fromalign=right,
fromphone=off,
fromrule=off,
foldmarks=no,
pagenumber=false,
refline=nodate,
]{scrlttr2}
\usepackage{lipsum}
\usepackage[british]{babel}
\usepackage{tabularx}
\usepackage{booktabs}
\setkomavar{fromname}{NAME}
\setkomavar{location}{\usekomavar{date}}
\begin{document}
\opening{}
\begin{center}
\begin{tabular}{cccccc}
\toprule
Item & Unit Price & Quantity & Sub-Total & VAT \% & VAT\\
\bottomrule
\end{tabular}
\end{center}
\closing{}
\end{letter}
\end{document}


Which successfully puts the date between the two addresses, but puts it extremely close to the bottom line of the from address (sometimes it superposes it onto the from address). It also doesn't fully right align the date, it is a couple of millimetres further from the right margin than the address above it is. My guess is that this has something to do with the overfull \vbox that XeLaTeX complains about:

Class scrlttr2 Warning: head of first page is 13.0448pt too high.
(scrlttr2)              You have to change firstheadvpos'
(scrlttr2)              or you have to define a smaller
(scrlttr2)              head of first page using \setkomavar.
(scrlttr2)              Because of this too high head of first page
(scrlttr2)              you've got an overfull \vbox message on input line 30.


I guess the solution is, as it says, to \setkomavar, but I don't know what to set it to.

\setkomavar{location}{\par\bigskip\raggedleft\usekomavar{date}}
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