Remember that the tIRA will have Required Minimum Distributions once he/they hit age 72. Roths do NOT have RMDs, so you want to preserve them if at all possible.
Most people recommend that they pull from the account at the end of the tax year, so that most of the withholding can be done in December for the annual taxes. Since you're hoping to encourage retirement now, perhaps your parents withdraw in January and December this year.
How much do they need from the accounts? If it's less than 4% annually, I would retire in a NY minute.
Has your mom elected SS yet? The typical advice is for the lower earner to file early, and the higher earner to file at age 70. Since it sounds like your dad is the high earner, I'd figure out sources of income, and then back into what they need from the portfolio.
For example: they need $70k. Mom's SS is $20k. So they need $50k from investments, until Dad files for *his* Social Security, That's only 4 years. So they withdraw $50k this year (Dad's age 66); $50k for 2022 (D: age 67), $50k for 2023 (D: age 68), $50k for 2024 (D: age 69) and $50k for 2025 (D: age 70, now gets his SocSec).
His SS is estimated at $30k. So starting in 2026, you have $50k in joint SS, and need draw only $20k from investments (maybe 25, given there's been no inflation adjustment - I leave that to you). ;)
Next: redirect the accounts to distribute dividends to the MM account.
After that: If you need more, pull from tIRAs.
Sounds like you're on the right track! I would totally get them away from the whole life, and from the FA - unless it's a CFP and a fiduciary.
The Boglehead forum likes the XY Planning network to find a fiduciary. Rick Ferri also gets a lot of thumbs up for a one-time consult (probably in the $3-$5k range).