Avoid icing conditions by avoiding any cloud when TAT temperatures are <10C
(my emphasis)
Not really necessary if you have high negative temperatures or more than +2-3 deg C. The "less than 10 deg C" icing criteria applies to the engines due to the venturi effect of the cowling and high speed of the air passing through. You are not going to get ice buildup on the leading edges at high negative temperatures or more that +2-4 degs C.
Hence you only have to avoid clouds and temp range of -10 to +5 deg C. If you have those conditions during approach = divert. Or ask for pilot reports from aircrafts ahead of you, if available.
If you have those conditions (unavoidable) during descent, inform ATC about your problem and make sure to get a clearance that will let you pass the layer unrestricted (no level offs and and free speed). Personally I would reduce speed to minimum clean and wait for the Total Air Temperature to hit -20 to -15ish, then I would increase to max speed as possible according to turbulence. A 130 knots speed increase should easily give you a 20 deg bump in the Total Air Temperature and a subsequent VERY high rate of descent to minimize the exposure through the layer (use vertical speed of -6000 to accelerate faster than using level change).
No need to panic. "Remain aloft" is not really a permanent solution either.
