1. I plan to backup photo for my trip.

2. I will be using:
a) Sony RX100 III
b) Sony action cam FDR X1000V

3. The video duration that can be shot in 4K using sony action cam is about 1H30minutes. (for 64gb 4K capable SDXC card)

4. I read the review the transfer rate for 64gb memory is about 1H plus using WD passport wireless.

5. So, I'm wondering is there any better options?

6. Buying cheap tablet seems an alternative choice.
By that, I can be really sure that I really backup the photos/videos vs blindly transfer using WD passport wireless.

7. Any other thought?

1. Tablet for directly transfer the photos/videos via USB. (and its windows UI, that's really easy)
The only downside is the cheap tablet usually come with small storage.

2. Phone (I'm using Iphone btw)
Cons:
- Limitation of the space
- Limitation of the supported format
- It's iPhone