The first question to ask is what is the goal of the change ?

If the goal is to have bigger diameter wheels to ride faster at the same pedaling speed, then changing the transmission (for instance a bigger chainring or a cassette with smaller sprocket) will produce the same effect for less money.

If the goal is to ride faster with higher performances tires that aren't available in ETRTO 355, then there is no other solution than changing the wheels.

The picture show the 20" Birdy with Schwalbe Kojak tires that are also available in ETRTO 355, this is not the best option since the Kojak have poor performances. The better option would be to use Schwalbe Pro-one or Schwalbe One.