If you have the USB image saved, there's nothing to stop you from just trying
But to answer your question: it depends on what your image is. Did you image the entire USB drive or did you image a partition?
For instance (full USB drive):
dd if=/dev/sdc of=my_usb_drive_image.img
or (for a partition):
dd if=/dev/sdc1 of=my_usb_drive_image.img
If your image is of the full USB drive, you should be able to write the image file to the bigger USB drive and then run gparted. gparted will allow you to resize a partition--letting you use the full space available on the larger USB drive. gparted will also run the necessary commands to update the ext filesystem (like adding more superblocks) to make the extra space usable.
If you have a partition image, it should be similar. But you will need to restore the image to an existing partition. That partition should be the same size as your original. Once restored, then you can use gparted to adjust the size of the partition like above.
I should point out that gparted is just a frontend for various tools. You could perform all the tasks gparted does by hand. But I don't remember the name of the ext program that grows/shrinks a filesystem off-hand.