Can I visit in winter?

Yes, but many trails in El Chaltén and Torres del Paine close or become dangerous. Only visit in winter if you are an expert mountaineer.

Is it better to fly or take the bus?

Fly between major hubs like Buenos Aires/Santiago to the gateway cities to save days of travel, but use buses for regional transit between towns.

Planning your first Patagonia trip: The ideal duration

You need 14 days to see the highlights of both Chilean and Argentine Patagonia without feeling like you are living on a bus. Anything less than 10 days will result in spending more time in transit than on the trails.

Choose your primary hub. Decide between El Chaltén/El Calafate (Argentina) or Torres del Paine (Chile). Trying to do both in under 12 days is physically possible but exhausting due to the limited flight connections.
Account for 'Patagonian Time'. Wind delays, limited bus schedules, and unpredictable weather mean you should add a 24-hour buffer to any tight itinerary. Never book an international flight for the same day you are taking a long-distance bus.
Prioritize your activity level. If you are a serious hiker, allocate 5 days for the O-Circuit or W-Trek in Chile. If you prefer day hikes and viewpoints, spend 4 days in El Chaltén and 3 days in El Calafate.

Can I visit in winter?: Yes, but many trails in El Chaltén and Torres del Paine close or become dangerous. Only visit in winter if you are an expert mountaineer.
Is it better to fly or take the bus?: Fly between major hubs like Buenos Aires/Santiago to the gateway cities to save days of travel, but use buses for regional transit between towns.