Hey ya’ll, it doesn’t seem like you can change the console resolution of a Linux guest running on HyperV, but you totally can.

Here’s how:

Edit /etc/default/grub with your favorite editor of choice.

Here it be:

sudo nano /etc/default/grub

Change this line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

To this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video=hyperv_fb:1600x1200"

Then in a console type:

sudo update-grub

I believe the max might be 1920×1200 but I didn’t try it, so I don’t know for sure.