maybe you should start road racing -

then there really isn't a point in doing a z2 ride that isn't 3 or more hours long.

personally 2 hr z3 or "tempo" type rides are my favorite training rides to do, I do them all year long. Z3 is a great intensity (for me) because you are just starting to ride kind of hard and feel like you are actually getting a workout, but it's not painful enough to require excessive mental toughness. Plus, you are beginning to go kinda fast so the sensation of speed makes it fun. I always try to focus on going as fast as possible (low back, relaxed shoulders, smooth high cadence, picking good lines in the road) without letting my HR go to z4.

edit: not that it matters for (heart rate wise) z2 for me is 150-165 bpm, and z3 is 165-175