Option 1 is good enough if you regular change the CVT fluid i.e. 2 years or 40,000 km which ever comes first.
In your case option 2 is better since the CVTF was never changed. Few other options are
- Change the fluid 3 times without opening the sump after every 1000 km. This will completely flush the transmission
- Flush the transmission fluid from cooler lines
The above two options don't required opening of transmission fluid pan/sump/chamber. Remember that the filter you find in the fluid pan is actually a strainer, not a filter. The transmission filter is behind the fluid cooler. Make sure you change that since CVTF is not changed for long time in your case. Don't try to clean it, just change it. The strainer could be cleaned and reused.
If you open the chamber, you will definitely require more than 1 pack. 2 packs are required exactly. The exact amount of fluid required depends on how long you leave the fluid pan open. The quantity for 20 min is 5.8 liters. Honda recommends not to leave the pan open for long durations.
Honestly the exact amount doesn't matter because I hope they will check fluid level from level check plug.
Because it's not required in case of Honda 
Only TCM reset is required if you replace transmission fluid pump or valve body which is done using HDS (Honda Diagnostic System).