I wouldn't, unless you have a much better than average cobbler they'll butcher them in my experience. if we can shorten them by 3" or more we can shorten them invisibly from the buckle end and restitch so they are as good as new.
I lost about the same amount last year - great for the figure, decimates the wardrobe though!
That is my fear. Looking at the stitching and how well made the belt is I don't want them to ruin it.
And yes the wardrobe is so difficult to manage. My tailor has done a lot to alter my suits and sport coats but there is very little anyone can do without throwing off the whole garment which sucks as well. Oh well