to spare

As a result of this winter's diversions, there is now carriage siding accommodation to spare at Wolverhampton High Level, and facilities have been offered to stable W.R. stock if necessary, as indeed it may be during the peak months of the summer service.

1960 February, R. C. Riley, “The London-Birmingham services - Past, Present and Future”, in Trains Illustrated, page 99

I did not really wonder, after sampling the "Settebello's" standards of comfort and service, that even on a midweek day in autumn there was not a seat to spare, despite the cost.

1960 March, G. Freeman Allen, “Europe's most luxurious express - the "Settebello"”, in Trains Illustrated, page 140