Too late now I know, but if this ever happens again, or happens to anybody else reading this, the thing to do is to turn the freezer back on, and leave it all to re-freeze.
The rotten meat etc won't smell nearly as bad when it's frozen, and you can hoik it out and bury it.
Yes - you will still have the freezer to clean, but you will have avoided having to deal with most of the stinking meat.
I dont think I have ever smelt anything as horrible in my life.
Too late now I know, but if this ever happens again, or happens to anybody else reading this, the thing to do is to turn the freezer back on, and leave it all to re-freeze.
TBH, this is what i'd probably have done. We had a big commercial chest freezer at one of our shops. It had been turned off, with the lid CLOSED for at least a year. The bottom of said freezer had about 2 inches of water in it, and everytime the thing was opened, the smell of damp and mould invaded the warehouse.
There was an identical freezer next to it, which was working, but it was low on gas and not cold enough, so the decision was taken by the fridge repair man to switch this old one back on (couldn't top gas up - these are very old freezers, running now illegal gas).
Lo and behold, the smell of damp and mould went within 20 minutes of the thing being turned on. And dealing with a solid block of "minging" is much more pleasant than dealing with liquid putrid "minging" (though i dont think the 2 inches of water was ever removed - health risks etc, fridge man promised us a new freezer!)