If you work remotely, then $3000/month is a great amount of money for Turkey. (Min. wage is around $300 in Turkey) Which means you'll have no problems financially whatsoever.
But you'll have language problems for sure whenever you need to deal with government officials or water/electric/telco companies.
If you can handle these, then you should be able to live a quality life in Istanbul and probably save half of your salary every month.