It is a little hard to comment on everything since this is a fictional fraction of whatever the OP's numbers actually are. As noted by others, I ran those numbers of 2.2M and spending of 125-150k, with a real tax rate of something probably in the low 20% range, and then two maxed social security benefits of $30k (which will also get taxed almost at 20%). Obviously with those numbers, it is impossible right now, the survival rate is 45% at 150k spending and 70% at 125k. The worst case in both has you running out in just 11-12 years, and living just on social security.
I doubt either spending level will work in just 1.5 years even at full time, you will need to get to 2.8M to be in the mostly safe range of 97% for $125k spending. So either you can't even switch to part time and need to work longer than planned, or you need to suddenly downshift your spending hard, which isn't really practical in just a bit over a year, unless you have done it for many years in the recent past.
I don't recommend not maxing your 401k just because it taxes you more later, you are in your peak earning years, and still need to save up a lot. Taxable is a terrible option for saving more money during peak earning years and when spending is $50k+, as you lose out on a huge tax benefit, even with almost no matching.