I'm good with sweating a bit - I tend to wear proper moisture wicking clothing anyway
The commute is 11km , twice a day. Single speed could work but there's some hilly parts and a lot of wind, which would suck. I like my gears. I just don't think I need more than 10 gears.
What bothers me with the "outside" gears compared to a gear hub, is that I cannot dump a lot of gears when I have to stop. It requires a certain awareness when riding. I hate starting with a very high gear, makes me feel I'm stressing the drivetrain unnecessarily. So in that sense, a 2x10 or 2x11 drivetrain might actually make sense because I can switch only the front cog and that can act as a "gear dump" ?