A thing which you will not need on a world trip is a flat at home. You pay the rent and you are not at home.
World trip and flat at home – Should I keep my flat in Germany?
Should the financial situation be given and the duration of the world trip is easy to grasp, you can use the possibility and keep your flat. It makes easier storing the household effects.
Subletting for this period could also be an option. However, on this occasion, the renter must mostly agree, besides, you are far away and cannot intervene, if the sublease fails.
Before the background of the long duration of the trip we have decided to dissolve our flats in Munich what means other challenges on the other side again.