Storage batteries are odd things. People tend to ignore them when they are doing what they are supposed to do (start an engine reliably and provide juice for lights and accessories), until they no longer work properly, then people tend to look elsewhere for other 'issues' and ignore the root cause, the storage battery is shot.
Myself, because I depend on my motor vehicles to start and run reliably in all weather, I replace my storage batteries every 5 years.
People also assume that cold weather kills the battery (when it gets cold like up here, the engine won't turn over). What kills the battery is summertime heat. When it gets cold, the motor requires more amperage to start and the battery that has become weakened from heat cannot supply that amperage anymore.
Glad it was the battery and not something else electrical. A new battery is an easy fix. Keep the connections clean and corrosion free and tractor on....