IGLOO have little lower static power, but are much faster
ice40 have slow internal ram and so
Maybe we are looking at different data sheets.
I see igloo ram working at 160MHz (DS0095 page 2.117)
and ice40HX at 403MHz (FPGA-DS-02029-3.5 page 29)
Depends on the iCE40 series you're looking at, I guess. The HX is not the lowest power of the iCE40, and it looks like the OP is looking for low power (especially static power).
I'm not 100% sure, but IIRC, some of the MachXO2 (/ZE) models have similar static power, and also have internal flash and a "standby" mode. They are slower than the IGLOO though and much smaller in LUTs. If I'm not mistaken, all iCE40 require an external flash chip.
According to EverydayMuffin, you have 10 years ahead, so that's probably good enough for a product unless you're targetting medical devices or military stuff.
One thing to note is that the future of the IGLOO series itself is unknown, if that matters. We dont' know much about Microchip's strategy. The IGLOO2 (that was before Mircrochip), AFAIR, already was not as interesting as the IGLOO in terms of power draw, so we could sense a shift in strategy.