Travelling to the USA on and ESTA allows you to stay in the US under the terms of the VWP:
allows you to stay in the U.S. for 90 days or less. If you plan to
stay for longer than 90 days, you must obtain a visa at the nearest
U.S. Embassy or Consulate.
A Canadian ETA is for entry to Canada by air.
visa-exempt foreign nationals who fly to or transit through Canada are
expected to have an Electronic Travel Authorization (eTA). Exceptions
include U.S. citizens and travellers with a valid Canadian visa. Until
September 29, 2016, travellers who do not have an eTA can board their
flight, as long as they have appropriate travel documents, such as a
valid passport.
Entry requirements for other methods of travel (land, sea) have not
changed.
You can stay in Canada without a visa:
A border services officer at the port of entry in Canada will
determine how long you can stay in Canada. Most visitors are allowed a
six-month stay from the day they entered Canada. If the officer
authorizes a stay of less than six months, they will indicate in your
passport the date by which you must leave Canada.
So it seems you will need to apply for a US B2 visitor visa for the US, but will not need a visa to enter Canada. However, it is up to the border service agents to ultimately decide your length of allowed stay.