I retired 9 years ago at 45. The ER plan I put together was in 2 parts. The first part was getting from age 45 to age ~60, the years I would be relying only on my non-retirement accounts. The second part was beyond age ~60 when my "reinforcements" would kick in. Those included unfettered access to my rollover IRA, my frozen company pension, and Social Security.
The further away from age ~60 you want to retire, the more money you will need in your non-retirement accounts to get to you to age ~60 when you will have unfettered access to more of your money. I was able to move half of my retirement account money (company stock) to my taxable account (without taking a huge tax hit) and that provides me more than enough monthly dividend income from a big bond fund to cover my expenses.
As long as I get to age ~60 intact financially, I will be fine because my financial outlook only gets better after that.
Like you, MJT411, I am single. Being that and childfree and debt-free (paid off the mortgage at age 35) were big reasons as to why I was able to retire 9 years ago at 45.