I'm in a similar situation: single, no heirs, 60 yrs old, NJ resident. I'm on the fence about Roth conversions, but have been doing small ones for a few years (< $20k/year). IORP tells me that if I do massive conversions over the next 5 years, I'll have a few more thousand in disposable income each year, but even without that extra money, I still have more than I can spend each year. First World problem, I know.
One thing I'm really looking at now is IRMAA. IORP tells me that if I do the big ROTH conversions it suggests, my Medicare costs will be somewhere around $2k/year, as opposed to $6k/year if I do no ROTH conversions. So even though I'm single with no heirs, I don't need additional income, I still don't see any harm in doing ROTH conversions. And I think I'd feel angry paying $6k Medicare costs knowing that I could have knocked that down to $2k. (I know that doesn't really make sense). So I might be doing some big ROTH conversions, just not as big as IORP suggests. I don't feel I need to totally empty out my tIRA, and I like the idea of having some tax diversity by moving more from tIRA to ROTH.
FYI, in the year you turn 62, you might be able to exclude up to $75,000 income from your NJ state taxes:
https://www.state.nj.us/treasury/taxation/njit7.shtml