You're coming from Long Island? Have you visited in the past 20 years? Any newbies to DL? (how old are they?)
And Only ONE day???!!!
If this is a once in a decade visit to DLR, you should plan for 4 days minimum (but that's a different topic

).....so let's assume you only have one day. Doing Nemo "first thing" would wipe out 45 - 55 min. of VALUABLE early morning touring & FP collecting time (as KC Mike mentioned).....time in which you could ride 6-9 fantasyland rides (4-5 not available at WDW).
If you had to ride it, do it in the mid-late afternoon when you need a rest anyways (& possibly when a parade is running?), or get in line at 3 minutes before closing time.
But with only one day at DL (or DL & DCA), I'd dump it off the to do list altogether. I know others like it.....but would they invest 8-10% of THEIR ENTIRE VISIT AT DLR dedicated to this fairly lame ride? It's a time eater & (imo) in the bottom 10% of DL rides & attractions.
If it was a relative of mine coming for one day, I'm recommend that they dump it. (& I'd be asking them why only ONE day at DLR??)