How can I teleport to an unloaded entity?

You can spawn a redstone block a certain numbers above or below the point of the player with an activator rail ontop. Then spawn a command minecart on the activator rail with the command /spreadplayers ~ ~ 1 false @e[name=PlayerHome,type=ArmorStand,c=1,r=2].

Because the /spreadplayers will load the chunk the entity is spread to, the commandblock minecart on the activator rail will permenantly keep the chunk that the armorstand is in loaded. When moving the point, run a fill command and a kill command at the previous home to remove the traces. When you are teleporting the player back to their home, you can simply offset the teleportation by a few blocks in the y coordinate.