I found this question trying to batch resize over 1000 SVGs. I first used an action to resize the content, but could not change the size of the artboard. The solution I found worked because SVG files are text based. I used a text editor that supports finding and replacing characters across multiple files. In my case the originals were 32 x 32 px and I needed them to be 20 x 20 px. I replaced every instance of 0 0 32 32 in all 1015 SVG files with ‘0 0 20 20’. That got me half way two thirds of the way. Finally I had to run a batch action to select all and align to center / middle of artboard. Et voila. Thought I would drop this here in case anyone can save their files to SVG or already have SVG files to work with.