US Xbox One in Europe ?

It most certainly can be... You are using a power supply that was not meant for the XboxOne, it may work, but if something goes wrong, you are the only person to hold accountable.
Please note that power supplies are not just rated by the 'Watt'
There is a voltage and a current that is required. In some cases, there are 2 or more voltages provided. The power supply is designed to provide enough current for each supplied voltage. The 'Watts' are simply a combination of the readings... Heck, a 1000W water kettle supply won't work for an Xbox360 or XboxOne... it's got the wrong voltage.
You are also quoting the total 'input' power usage... not the actual output of the adaptor. You need to be sure the 12V and 5V supply are within range.

 

I would check local pawn-shops, used electronics stores, perhaps e-Bay for an entire replacement adaptor for the Xbox. It won't let you run other appliances like the voltage transformer but will most likely be cheaper if you find a good source.