Question for you.... are you suggesting to use the Oak as a sub-floor? or as a sub and actual floor (2 layers)??
Thinking out loud here - the T/G oak floor would likely shift quite a bit as a sub-floor. Not to mention the weight. If you added a 2nd layer..... more weight....!!!
My thinking, while admittedly based on 0% actual experience!, is that a 'normal' sub with oak over the top would be a great (but heavy!) choice for your TT floor.
Please be sure to keep us posted on your thinking, questions, and the process as you go forward.... maybe others with actual life/trailer experience can offer more thoughts....?!