With all TD mortgages sign them at 25 year weekly or bi weekly. Then you can change the amortization period any time.
So you make it 20 year and your payment goes up 1/5 and all that goes on your balance. When I worked we had seasonal over time, I would drop the mortgage amortization by half my Sat. Sun money. And the other half yep yep yeppee.
Yes 500k for me is eye popping but with the op income their is no reason for not going mortgage free in reasonable amount of time.