I've gotten burned out before and had to take time off. But I think as long as you're still curious about how the long rides will feel and what they are like, you are okay.
I firmly believe that it (burnout, disillusionment, not wanting to ride again) is not going to happen in one ride. The most that will happen is you'll want to take afew days or maybe a week off. Then you'll be wanting to ride again. Especially given how far you've come and how enthusiastic you are. And I believe you still have a lot of untapped potential.