Yes, you would need to use a custom node with tex2Dlod. For a better parallax effect you can also chain up multiple BumpOffset nodes (alternatively rebuilt the bumpoffset nodes and include a multiply by normal.z) - this will help greatly to reduce texture swimming at steep angles.
Curious if there's a way to use LODbias via a material node? I'd like to use a lower mip of my height map for BumpOffset, since simple parallax often works better with smoother maps. I guess I could just manually downsample in Photoshop and import another texture...