Canada doesn’t like people who declare non-residency for tax purposes and then return shortly afterwards. The CRA will pay extra close attention to you after you file your tax return upon returning. If they determine you didn’t cut enough residential ties or didn’t establish strong enough residential ties elsewhere, they will consider you a tax resident for the time you were gone and you will need to pay back taxes. In the coming years, the CRA will probably be even more strict since taxpayers are on the hook for programs like CERB due to covid-19.
If your goal is to save money on taxes and be a digital nomad, you will need to establish strong residential ties with a country and cut all primary and the majority of your secondary ties with Canada. There are lots of alternatives to Estonia for establishing residential ties. Such a place would ideally have a double tax treaty with Canada and some tax advantages. Some countries that come to mind are Chile (first 3 years are tax free for foreign income), Mexico (Relaxed on foreigners with foreign income), Thailand (No taxes if foreign income remitted after 1 year). You could also opt for a country with low or no taxes on foreign income and a double tax treaty with Canada (e.g. Dubai, Hong Kong). Countries such as these will usually require you to obtain a residence certificate to become a resident for tax purposes.
If your goal is to simply travel and be a digital nomad, I’d stay as a Canadian tax resident since you could keep Canadian ties and not have to sacrifice your time and resources escaping the Canadian tax net.