If people aren't pooling resources for either brute or kangaroo or bsgs, then it will be a long wait unless you have Zielar's equipment then #120 is doable within 2 months +/-
There is a pool for #64 and I have tried to get people to pool resources with bsgs and kangaroo but I guess everyone thinks they can solve on their own.
And I believe you are correct, whoever finds #64 must pay high trans fee to get in into a block before someone else attacks it with kangaroo.
There is a pool already running. I think someone did the math for 64 and still 1 out of 800,000 to find the key after breaking the shares if I am not wrong. The pool is running less than 20 people, not sure about it. I don't think it's plausible to find 64 alone, unless someone is really lucky hitting a jackpot by using random. I have my own rig for Ethereum but far from enough to run Kangaroo. Even if I have enough to go for it, I prefer to choose safer path continue mining Ethereum because if you do the math, it has no difference putting 2 months for 120 and it's not a guarantee you will hit the jackpot. Just doing some fun things on puzzle, who knows I might be the lucky to hit jackpot since my old GPU can't mine anymore.
Just for your reference. Let's say you have 256 RTX 3080 with current price, you are going to get about USD 7.50 nett daily on each.
1 RTX 3080 = USD 7.50 nett daily
256 RTX 3080 = USD 1,920 nett daily
USD 1,920 x 60 = USD 115,200 2 months
The award not even near even if you just need 128 RTX 3080
But if you had your 3080s and your friend had theirs, etc. etc. you could solve #120 quickly. But to just solve for #120 is a waste, IMO. Target 120 through 160, at least the range, then all wilds can be tamed and all be in the same range not in lower 1/32 range.
Also, if you have 256 3080s, mere 1.2 BTC is nothing and you are obviously in it for mining, but if you only have 1 and you have friends who have 1, that is the combining power effect where maybe you can net more than mining with 1 card. Who knows. It's fun, it's a challenge, next one breaks the world record...
The #64 pool is only as good as the number of people who sign up for it and actually run their rigs for awhile. But it is an enormous task, no doubt. Running same power with Kangaroo, the 120 would be found first.