it depends on your store. I'm taking over two weeks off but got prior approval from my ETL and STL and am taking over two weeks off without a LOA. The system won't let you ask off for more than 10 days without taking an LOA but you can request the days off in more than one request and it will accept it. There are several other people in my store who have also done this.
I don't think if i just asked for two weeks off without asking before hand that they would approve it. I went to my ETL about 4 months ago and explained that i wanted to take this trip and she gave me the go ahead to take off as much time as needed. I also planned to take my trip during a down time so that it would be easier to have my hours covered vs when we were busy.
i didn't have anyone to cover me either and they are having me train someone to cover me while i am gone. After reading a lot on this site i've realized that i work in a really awesome store. Our ETL's are awesome and are ALWAYS willing to work with anyone. As long as you come to work, do your job, and have a good attitude they will do what they can for you. Hopefully they will be willing to work with you too since it's so far in advance. I'll cross my fingers for you!!