Hi,
Planing a north to south trip from 22 to 31 Dec. I don’t think there’s enough time cover all the must-see, so am just going to pick some but not sure what to pick / drop.
Am going with my 2 teenagers. We are NOT into shopping, night life (drinking, parties, we don’t mind night markets), adventure. This trip is mainly for us to spend some relaxing family time since we have never gone for trips as a family. It’s a first time for me planning a trip (usually I just follow what my friends planned

). Some ideas/suggestions will be greatly appreciated:
Hanoi
Given that it will be winter in this region with gloomy skies, is Ha Long Bay still worth going since it basically scenery and water activities. Too misty / cold?
No time to do Sapa and I think I can’t take the long hikes (old bones hahaha) so dropping this.
Da nang
From what I searched online, it will be rainy season. Does staying in a beach front accommodation still make sense e.g my khe beach area
Hoi An
I’m considering either a day trip or part of a day trip (with monkey mountain etc) which will be about dinner time when we reach Hoi An, we will have dinner before heading back to Danang. Is Hoi An worth to spend a day?
Hue
Dropping this since it’s seems to be mainly
tomb attractions and long drive from Da nang. Or should we go anyway?
Ho Chi Minh
We have 2.5 days here. Planing to do day trips to cu cu tunnels and Mekong river. Is 2.5 days too many, should I reduce to 1.5 and add 1 day to either North / Central?
Lastly, any advice on what to pack for Hanoi? I mean is long sleeve/pants + warm jackets enough or should I pack thick jackets and glooves? Thinking of just packing Uniqlo’s heattech innerwear layer with long sleeves & pants.
thank you and sorry for the long post.