How to reduce power consumption in level shifter
Allow me to share with you the circuit of a levelshifter as is used in many ICs:







simulate this circuit &ndash; Schematic created using CircuitLab

It uses 8 transistors, which looks like a lot.

But this is what is used on a chip so transistors can be made extremely small.
On a chip this can be made to work up to GHz frequencies.
When static (the input signal does not change) the circuit consumes no current.

It is nearly impossible to build this circuit on a PCB using discrete MOSFETs and get similar performance, you'll be lucky to make it work at 10 MHz. Discrete MOSFETs aren't designed to be used like this.

Fortunately chip manufacturers put this circuit (or something similar) on a chip for you to use. Just search for "levelshifter" and you should find a suitable chip to do the job.