The game certainly is one of the best selling fitness games that don't have "Wii" in their name. I wonder how many of those sales were because people wanted to stay physically active during the quarantines.

Expecting somewhere between 1 and 5.84m. Watched some vtubers playing it, looks like a good time!

Now this is the hard one to predict.
Obviously the game exceeded Nintendo's original expectations and has been doing damn well for a while now, selling at a pace second only to MK8 and AC. But there's no telling exactly how long it will keep up that momentum.
If I have to predict a number now I'd say around 20 mil, but it wouldn't suprise me if that ends up being off by quite a bit in either direction.

10-12M at most

Sales got Spiked hard thanks to Covid, but i dont think it’ll ever outsell WiiFit anytime soon (especially post covid when you got Nike App instead)

Its a really good game nonetheless and helpt me sustaining my weight during lockdown.

I’m a believer of 5mil in japan. So WW I’m going with 12mil.

BQ: not yet, I want to buy it to play with my wife and kids. Hopefully get it in the next few months

It's definitely hard to predict.  I voted 15m-17.4m, but I can see it going even higher.  Check out these legs:

December 2019 - 2.17m/2.17m
March 2020 - 0.56m/2.73m
June 2020 - 1.17m/3.90m
September 2020 - 1.94m/5.84m

Last quarter sales were almost as good as launch quarter.  This quarter sales are likely to be higher than launch quarter.  The easiest mistake to make in projecting RFA's sales is to think it will sell like most other games.  This is a Blue Ocean title.  It's selling by word of mouth to people who would normally not get a Nintendo console.  COVID gave it a boost, but that doesn't mean it's a temporary boost.  Instead it's more like free marketing to people who normally don't buy consoles.  Now that word of mouth has gotten out about it, it's going to keep selling even after COVID is over (and COVID will still be around in 2021).  I may very well be short changing it at 15-17.4m.

Bonus: Don't have this yet, but I am likely to get it at some point.

It was supply constrained launch quarter, This will probably be one of it's best quarters, and the game will likely have legs for years. I doubt that Covid has helped it much. Going with 14mil, but wouldn't surprise me if it reaches over 20.

12m is my guess.

I voted 10-12.4. Could be a lot higher but i'm a believer ring sports will make an appearance, somewhat slowing it's sales down in 2021/2

I'd say 10 million.

Edit: Decided to increase it to 15M.