[Dominik]

From a welding point of view, yes: possible. If they know what they are doing. Any good fitter and turner with welding skills can do this, if she has a big enough lathe to cut the rim and line up the three pieces.

You might find that a wider wheel, assuming you can source it, costs the same as the modifications. Or similar.

And you get to keep the two wheels when you buy two more :-)