How can I keep the road trip low cost?

Hi!

I wanted to take a road trip across a few provinces in Canada. It's a total of 40h, but I would like to avoid spending more than 4-5h a day driving, so let's say I am gone from home for 14 days. From Montreal, to New Brunswick, to Nova Scotia, to Prince Edward Island and back to Montreal. I want to take it slow so I can work at the same time in the hotel or in cafés.

If hotel is like 150$/night, I eat for 50$/day and spend 800$ on gas, it's 3500$ for a road trip across small towns in Canada. Quite expensive haha!

How could I make this trip less expensive?