Is your mother able /healthy enough to travel by herself?

It is very meaningful for you to bring your ashes to his homeland, but is not possible this could be given to your mother if she goes alone? She is his wife, no matter what you think.

You need to ask yourself priorities when you visit Denmark --is it more to visit relatives and his good friend in memory of your father or delivering his physical ashes have equal parity/value?

Personally I would like to meet relatives and learn more stories about a loved parent who died. Talking about your father with others in a pleasant storytelling way, is a special type of memory and a visit to always remember for the rest of your life.

By offering the ashes to your mother to deliver/rest, puts the ball in her court ....by herself. Without her daughter beside her to do this task, to influence her feelings about how she feels about her husband in now.