You could resize afterward, but simpler might be to just do a file-by-file copy, something like this (assuming the new target is /dev/sda in this situation):

mke2fs /dev/sda1
tune2fs -c0 -i0 /dev/sda1
mkdir /new
mount /dev/sda1 /new
mkdir /old
mount /dev/sdb1 /old -o ro
apt-get install mirrordir
mirrordir /old /new
umount /old

## and now the tricky part: try to install the MBR bootloader:
grub-install --root-directory=/new/boot /dev/sda
umount /new

## done

Cheers