I think it will be tough. I took a prep course without Orgo II and for me, it was just a mental thing. I would always use it as an excuse for not doing well and use it as a crutch. It was a self-esteem/confidence thing to me. I ended up not signing up for the MCAT that sem. But if you can handle that course load, and do extra work on top, I say all the best! Plus, for you, you will not have a good grasp of Orgo I in Jan or early Feb. Realistically, you will fully understand everything in April, but in the early prep work of Jan/Feb you will not have a decent grasp. I guess you will feel confident about what you know in Orgo I in March, when your class has studied the topic for at least a couple of months. Adding a good understanding of Orgo II in that three month period will be difficult, no doubt. Very tough road ahead, but if you have the dedication, go for it! I have read a few posts (maybe 1 or 2) from people on this forum that have taken the MCAT w/o Orgo II and done really well on the test.
Overall, I think it is the amount of time and dedication you put into it. If you put an overwhelming amount of energy into this endeavor, you will do fine. That seems to be the recurring theme about this MCAT discussion.
Maybe getting the 1001 Examkracker Organic Chemistry question set will speed your process along. I haven't heard any good reviews about this particular set but it sounds like it would be useful to you.
Hope this helps.