Complex sentence: Instant City is a mobile technological event that drifts into undeveloped, drab towns via air (balloons) and erects provisional structures (performance spaces); the whole of which is intended to eventually move on leaving behind advanced technology hook-ups.
Split into simpler sentences: Instant City is a mobile technological event that drifts into undeveloped, drab towns via air (balloons) with provisional structures (performance spaces) in tow. The whole endeavor is intended to eventually move on leaving behind advanced technology hook-ups.