Never going to fit all EU on my 2GB US/AU 1xxx units Loly. Maybe EU 1300 has more space, but I can't even get all NA on mine 'cos without any files at all there's only 1.85GB free and the full NA image is now 1.88GB. It's still got the oem US & CA 2011.10 on board and I haven't updated the 1490 for AU recently, but there was only ~18MB free even with the smaller old AUNZ CN so i have sent this successfully:

del,0:/.System/JCV/D1279060A.sum
del,0:/.System/JCV/D1279060A.JCV
copy,1:/D3531080A.JCV,0:/.System/JCV/D3531080A.JCV
copy,1:/gmaptz.img,0:/.System/gmaptz.img
copy,1:/gmapprom1.img,0:/.System/gmapprom1.img
copy,1:/TrafficProvider.xml,0:/.System/TrafficProvider.xml
reboot

Update.log shows:

nüvi 14xx Series Software Version 6.20, UID: 3xxxxxxxx7, HWID: 3xxxxxxxx7
------------------------------------------------------------------------------
Parsing "del,0:/.System/JCV/D1279060A.sum"
Success
Parsing "del,0:/.System/JCV/D1279060A.JCV"
Success
Parsing "copy,1:/D3531080A.JCV,0:/.System/JCV/D3531080A.JCV"
Success
Parsing "copy,1:/gmaptz.img,0:/.System/gmaptz.img"
Success
Parsing "copy,1:/gmapprom1.img,0:/.System/gmapprom1.img"
Success
Parsing "copy,1:/TrafficProvider.xml,0:/.System/TrafficProvider.xml"
Success
Parsing "reboot"

So it's now got ~38MB free with AUNZ 2014.20 and the other files updated.

@tik0
Your problem is always going to be that you don't know how much free space you have, whereas i can connect in msm long enough to ascertain that and also see files names and their size to know what to delete to make more space. You'll be playing 'blind man's bluff' unfortunately, but if you run out of space you will get an error in update.log telling you that there's insufficient space to copy.

Really in your case you are probably better off putting as much as possible on a microSD card like dasilvarsa recommended so as to minimise the risk of bricking. Unlike you, I can at least still access preboot with difficulty and i also have the option to repair the usb socket.

You seem to be sorted now, so i'll mark this thread as solved.