IIRC Boeings almost universally have fuel heaters using bleed air. Although that doesn't address tank soakdown temperature, it does ensure fuel reaching the engine pump is warm enough.
A C-172 fuel tank would cool down much faster than a 747 (surface-to-volume ratio and all that...) If fuel temp is such a concern, I'd think some heater (either in-line, or in the tank, such as "spillback" or pump excess flow) would be necessary.
BTW, the pireps on the Thielert 172 discuss much improved altitude performance over the standard ship, mostly due to the constant-speed prop.
