I have a TomTom XXL GPS...  I'm thinking it's 3 years old.  I paid extra to get Life Time Map updates since my previous didn't have this. 

I just went to download the latest map Updates & I get an error message Not Enough Room.  Apparently I'm not the only one:  http://uk.support.tomtom.com/app/answers/detail/a_id/12911/~/not-enough-space-to-update-the-map-zone   Frankly I don't need the whole US, Canada + Mexico and some devises you can free up space by loading the region you need.  NOT my XXL which requires TomTom Home 2 with no option for regional maps. 

I think I got it to downloads but only by deleting services I wanted.  I doubt I'll be able to do this next time.

There's no provision for an SD card like some used to have to expand memory... 

Perhaps TomTom think they are clever & will forcve me to disguard a working devise & buy a new one.  It might.  But my new one will be some other brand. 

I have that very same model and just updated yesterday with the same results you reported.

 

I went into the tab that shows map versions on my computer (don't ask me why, but I was just trying anything).  There I saw probably 8 or more versions of the US maps.  Each of these versions were 1600+ to 1800+ MB in size.  So I tried to open the "more detail" link on each file to see if I could find dates on the files.  No luck but they had version numbers so I picked 4 or 5 of what looked like the oldest versions and just deleted them.

 

Then I went back and did the update routine on the GPS and worked.  When it finished and I went back to the first page of the TOM TOM Home there was a not at the top that said my maps hadn't been updated for something like 20 weeks.  I asked it to update the GPS and it had a small file that was listed and I checked it and the update went through and finished out properly and indicated the maps were now up todate.

 

It seems to be working ok, after the update with one slight exception that I have found.  I no longer have any of my favorites saved.  So evidently one of the older map files I deleted off my computer had "my favorites" in it and I must have blown it away.

 

That wasn't a serious problem because they were just addresses of my family members.  I can re-create them in a few minutes.

 

Don't know why this works but it did for me.

I did delete a bunch of files, hoped I chose to keep the newest.  My theory was the newest map would be on top.  I clicked on the details of each & didn't see a date (of course, I was looking for the smaller regions like the Support article suggested.)   I won't know about the favorites until I get it back in the car.   

It always takes forever to do updates over my wireless.  I think the HOME software is the crappiest set up.  I liked my old Magellan operation but when I bought the TomTom, Magellan hadn't begun offering life time Maps.  (I said at the times, all GPS would have to follow suit or they wouldn't sell units...  and now they all do.