Is it possible to relocate the rootfs to SD card?

After ~18 monts of moderate use, my Jolla appears to be dying. (As well as the entire Jolla itself, but this is a separate story.) First, some spontaneous errors come, e.g. portions of text are replaced by garbage, or color palette in particular apps is skewed. Then the system crashes, and after a long reboot it come up in a pure factory state. Looks like flash memory is being corrupted, and reset to factory state on the next reboot. Load all the updates, install the apps, make my personal settings again from the ground up. But this is not for long - the same thing repeates again in a couple of days. As other parts are still working properly, is't there some easy way to redirect the rootfs partition to the SD card? E.g. by editing some text or hex files (in Developer Mode, of course)? So that the bootloader would recognize a blank card as "corrupt", restore the factory roofs to it, and continue using it from that point on. Or would it be possible to dd the flash partition to SD card, and then chroot to it once - right after restart (while the system is running properly)?