"We are outside of our country."
Translation:Ni estas ekster nia lando.
No, because "estas" does not mean "leaving", and is not a verb of motion, so adding the accusative seems odd.
If you used "Ni iras ekster nian landon", then yes, that would be "We go out of our country".
Although the English sentence is perfectly understandably, the "of" is unnecessary, and adds a complication to someone learning Esperanto. It sounds far more normal to say, "We are outside our country".