I'll take a stab at this....

When we de-ice there are are different types of fluids we use depending on the situation. Factors include outside temperature, type and intensity of precipitation falling that is prevailing at the time. I'm assuming you were sprayed with Type IV, so :45 is well within the holdover time allotted for anti-ice effectiveness. This is completely independent of any flap speed issue, not related at all.

As a pilot, a flap speed issue is not a big deal. I'll go as far and say I'd love it if they threw that softball at us in the simulators during recurrent training! However, flap irregularities are still considered part of the flight controls and any flight control malfunction for the most part automatically requires an emergency to be declared.

Not minimizing the circumstance because I've been in the back during a mechanical emergency before, I know it's not fun. But in reality, your situation was very manageable by the cockpit.