Ha Giang Loop March 2025 weather? Last minute booking?

I'm going to Vietnam at the beginning of March and I'm unsure about the Ha Giang Loop. I've heard from people that it's the highlight of their trip, but I'm concerned about the weather (it might be misty).

-Does anyone have experience with the Loop in early March? How was the weather (misty)?

• Plan B is to wait for the weather and book the Loop last minute. Does anyone have experience with this? How far in advance are weather forecasts reliable? And how far in advance do you need to arrange buses and trains in Vietnam?