Some BJJ questions

[SNOWBALL]

The Rickson Gracie International Jiu-Jitsu Center is around the corner from my apartment. I've been studying Jeet Kune Do since early august, but recently had to quit studying with my Sifu because private lessons are too expensive for me. I still take free semi private lessons with a different Jeet Kune Do guy once per week. He has been seriously practicing various martial arts for more than 12 years. He trains more than 20 hours a week in JKD, Kali, and Japanese Jiu-Jitsu. He's pretty ecclectic, and I don't agree with everything he does, but the price is definitely right, and I think my training with him has some real value. I also meet up with a training partner once a week to work on striking.

Anyway, I'm thinking of taking this BJJ class. I have a few questions.


1. Assuming I go 3-4 times a week, how long will it take for me to be able to use BJJ in a real life encounter?

2. People tell me thta BJJ is VERY cardio intensive. Will my training in JKD and BJJ help my conditioning enough for me to be able to participate effectively in BJJ, or will I need to do supplemental conditioning outside of class?

3. I'm also thinking about going to a JKD school that offers weekly BJJ classes. If I only train once a week in BJJ, will it be worth anything to me, or do you need to train more often to be able to use BJJ stuff?

Thanks in advance for any help.