I'm not sure about that,
but the doors when Riker and Worf encounter the boarding party seem to indicate that happens on deck nine. I'd assumed they were cutting them off there, having redirected to intercept them off-screen, though if you're not reading the door visible in one split-second shot and just taking the dialog, it certainly seems like they went to deck 29, Riker followed the Viceroy down to deck 30, and then they landed on a ramp on deck 31 in a shaft that extended down to something like deck 40 (it's a little hard to tell whether there are one or two crawlways entering the shaft per deck).
The script on-line says "twenty-nine," though. It could've just been something the production team did on their own initiative when they were breaking out the script and trying to figure out how to make a bottomless shaft that starts at the bottom of the ship. Just imply the fight actually took place in the middle of the ship, and the Remans made it pretty far up before they were stopped.