It never ceases to amaze me how well built this bikes are.
The flat 6 used in the valkyrie is resilient and reliable. Remember it came from the Goldwing, where it is totally wrapped around tupperware.

Back in 2015, I did my 3300 miles ride through 7 States (California, Oregon, Washington, Idaho, Wyoming, Nevada) with the radiator fan motor broken (i.e. it wouldn't engage).
The bike faced temperatures ranging from 55F to 107F, elevations from 3ft to 11000ft and *never* showed the overheat light (I tested it before leaving to know if it would let me know if the engine was overheating).
Basically, as long you are moving, the engine shouldn't overheat, unless there is something else wrong (broken water pump, clogged radiator, etc).