I have 2 exactly same models (old TomTom XXL)
and on one I have DE_AT_CH_1100_11657 and United_States_1GB_1100_11707 maps
and on the other only DE_AT_CH_1100_11657

I tried to copy paste the United_States_1GB_1100_11707 to this other GPS device but I get an error with red screen like "you can't use this map"

Is there a way to make this work???

How?

The answer is simply YES, you can make it work by using the FastActivate.exe

Just copy paste the map into root of your Navigation and run FastActivate and chose option 2.
- Patch Maps

and it will make the map work with the device... Mine works now.