This is what my den victoria-reginae looks like today. The larger old cane remains unchanged, while the young new one seems to be rapidly giving up. The picture actually shows the yellowing of the cane even more clearly than the naked eye.
Instead, all the rapid growth seems to be happening at the base of the orchid. Two new roots (as I first noticed here) are now clearly visible. Meanwhile, the little bud off the old cane (at the bottom of the picture) seems to be the start of a new growth. I've been misting the roots every couple of days to help get more moisture to the plant, while still keeping the watering on the sparse side.
A desperate attempt at survival
This rate of growth is quite rapid considering that this is what everything looked like this just 3 weeks ago:
Now I just have to hope that these new roots survive once they penetrate into the growth media.