The house is lovely and does not look unbalanced. Would moving the front door to make it symmetrical involve making changes to any interior walls etc? I suspect your proposed project would be tremendously expensive, full of headaches and unintended consequences, and give you zero return on investment.

Mount Vernon has the same issues!

I guess if it was good enough for George Washington, it should be good enough for me :)

If you found the right columnar, narrow tree and put it to the left of your stoop, you'd reduce tthe impact of the assymetry. You'd want something that isn't going to get too big for the spot, but will rise at least a bit above the first floor.

Your landscaping isn't symmetrical, so this would totally work.