Thank you for using JustAnswer.
I'm sorry to hear about your situation. First of all, yes, you can move to Tennessee, but every state has a residency requirement. That is, you will have to have established residency and one of the spouses must be a resident for 6 months prior to filing. So while you can move to Tennessee, you will need to do so 6 months prior to filing.
As to how long it would take in NY, it's really hard to say for certain, as each court has a different docket, and some courts are more backed up than other ones. An uncontested divorce would probably take about 3 months, and contested 9 months on average, but that's entirely contingent upon the court, the issues presented, if there are children, etc... 3 months is a good rule of thumb once you meet the requirements for divorce
Hope that clears things up a bit. If you have any other questions, please let me know. If not, and you have not yet, please rate my answer AND press the "submit" button, if applicable. Please note that I don't get any credit for the time and effort that I spent on this answer unless and until you rate it positively (3 or more stars). Thank you, ***** ***** luck to you!