Minimum width for a bar

[Nick Payne]

How can I specify that a bar containing only a single tied note be a certain
minimum width? Because the note is tied, I tried using

\once\override Slur #'minimum-length = #16

That works if the bar is in the middle of a line, but it doesn't work at the
end of a line, which is precisely where I need it to prevent text
indications from going right out to the page edge. I had a fair hunt through
the documentation without finding a solution.

Nick

middle.png
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end.png
Description: PNG image