Plots: reducing subplot size


I’m making composed plots where the legend would be the same for each subplot. As such, I want only one legend for all plots and it would have to be next to the grid layout. At the moment I can only set label = "" for all but the rightmost subplot but this gives a squashed legend because the subplot is narrow.

I would like to know how I can make a subplot that contains only a centered legend. At the moment I can do

l = plot([], [[],[],[]], axis = false, ticks = false, grid = false, label = [" Label 1" " Label 2" " Label 3"], legend = :inside) 

But this is in the middle of a large blank square:


Any suggestion ?