Designing Kitchens and Bathrooms - In over our heads

We have had to gut our masterbath due to water damage. We have taken up the tile flooring, removed the toilet, bathtub walls to the insulation, etc. but we are now in over our heads.
In order to fix the floors (laundry room flooring, floors in half the bath) the tub has to come out b/c the floor under it is rotten. It is a 1986 style oval tub and it's quite large. I don't see any way of getting it out without busting it up. And I don't see any way of getting another tub in the house that is just a large (which I love). So, after a long post my question, how on earth would we get a large tub back in our master bath??? Is it safe to say that we'd have to take out some walls or are we stuck with replacing it with just a stand up shower? I'm sure they don't make tubs that you piece together -ugh, we're in deep now. Thanks for any advice!!
-D

Is there a reason to not re-use the current tub?

Large tubs post construction are tough. Your solutions are what you have available to you (with the exception of a multi-piece tub, I do not know of any)

You shouldn't need to completetly remove the tub to repair the floor. Most large tubs are fiberglass which makes them easier to handle. Once the surrounding tile and drywall are removed, if there isn't room to slide the tub out of the way you should be able to raise it enough to repair the floor. Be sure to properly support the tub so you don't damage it.

What is the width of the door opening with the door removed from the hinges?
What is the height of the tub?
You should be able to turn the tub on its edge and remove through the door. Good luck.

Our master bath door opening is approx. 20" while the tub is at least 28" so it won't get out the door in one piece. Once we pull up the tub to repair the floor, the area is to tight that it will only give us about 8 additional inches to work-that leaves some flooring (or I should say, an open hole area) that we really can't get to to replace. Our original plan was to rock the tub on its side and fix the floor, rock back and fix the rest of the floor but the tub is so big! We consider ourselves intermediate DIY'ers and just can't figure this one out. Thanks-

I had a similar situation a couple years ago and finally had to give it up and resort to the old rip and tear method. The walls around the tub were not plumb so raising it up was not an option without re-framing them, the rest of the walls had been sheet rocked after the tub was in so I couldn't slide it forward, and the tub dimensions diagonally didn't allow it to be pivoted in the space it occupied to stand it on end and work around it. The sawzall worked great. The next issue was getting the new one in. I've been on job sites measuring for flooring in the frame-in stage and those things were already installed. They're put in place even before the wall with the door is framed. Short of tearing out all the sheet rock and the wall the door is in, I couldn't get another one back in. The choice was a much smaller tub, tear all the sheet rock and the wall with the door out, or a really nice big shower with no tub. I had three bathrooms, all with tubs, so now one is a really nice big shower and the other two have tubs.

20" seems like an awfully narrow door opening... even my pantry door is 24". Might be a good excuse to put in a nice 32" or 36" door :-)