Yellow/ brown TTTF winter lawn.

North Carolina, USA.

"Triple Threat" TTTF

History below:

Problem: yellow and brown leaves, worse in one area. History of leaf spot and rust this fall. Overall lawn not deep green. Should I:

A.) Leave it alone. It's winter, lawns don't look perfect.

B.) Fertilize to fix deep green, help grow out diseased areas. Temps are freezing, but where dogs have peed is deep green and growing faster.

C.) Fungicide treatment (propaconazole, azoxystrobin, myclobutanil, etc.) Would this even make a difference? Is fungus really a problem in winter? Fungicide still effective in freezing temps?

D.) Some else?

Current temps freezing overnight, 40-50s daily. Occasionally in 60s.

Over seeded in September, TTTF Triple Threat, followed Nilesandstuff over seeding guide. Core aerated, topdressed. Fertilized with Green Eagle Starter fertilizer at about 1 lb Nitrogen per 1000 square feet late September. Per @Nilesandstuff's recommendations, I have stopped prophylactic fungicide use to improve soil health. Irrigation shut down mid November.