Estonia sounds like a fake country where a devious masked wrestler would hail from back in 1986. Just saying.I have had the same experience. Even in Canada, they usually accept either CAD or USD.
And as far as the Bitcoin values across the world, you look at it this way: A lot of these countries' currency is almost valueless. When you can get a currency that will allow you to buy internationally from much stronger countries, you will try to get hold of it. I've been to Mexico, Canada, Jamaica, and the Dominican. Canada is the ONLY country where they have shown a preference to being paid in their own currency. Everywhere I've gone in Mexico, Jamaica, and the Dominican I've been quoted prices 100% of the time in USD and if I want to pay in their local currency they usually need to get a calculator to figure out how much I owe them, and they usually do not make change.
I've never seen a place here turn down American money although I am sure there are some. Thing is the exchange rate is usually lousy in a shop or store so you're better off converting to Canadian at the best rate possible before you come here.