It depends . . .
Knowing that my town only interviews applicants (including renewals) 1 day/month I dropped my Wife's renewal paperwork/check off in Feb for an Aug renewal. Earliest interview was May. She had her new LTC in-hand a month after her interview. That was last year ago now.
For my next renewal, assuming I'm still in MA at that time, I'll do it at least 5 months prior.
We just put the new ones in the safe until the current one expires. I'd rather have it a few months in advance than sweat out delivery before expiration . . . even if the current bill passes as written.