Thanks - with the exact words to search, I was able to find the Florida statute. Relevant section reads:
"(b) If consent of the donor in a record cannot be obtained by reason of the donor’s death, disability, unavailability, or impossibility of identification, a governing board may modify a restriction contained in a gift instrument regarding the management, investment, or use of an institutional fund if the fund has a total value of $100,000 or less and the restriction has become impracticable or wasteful; impairs the management, investment, or use of the fund; or if, because of circumstances not anticipated by the donor, a modification of a restriction will further the purposes of the fund."
I think this is exactly the situation we find ourselves - definitely hit the "size of fund", there is nothing listed in terms of timeframe. Clearly we cannot get the donor's consent due to death. "impracticable and wasteful" seems to summarize in three words why I want to do this. Does not appear we even need to notify the AG - that process is spelled out in section C for amounts from $100K to $250K.
I guess the relevant board would be our endowment committee which is specifically empowered to make investment decisions, but if they agreed with the change we could also run by the church's board of directors to further cement it is a good idea. People get weird about our endowment (see "we need a 2/3 majority at a vote with a higher quorum requirement than changing our bylaws" above), but this does not rise to the level of a congregational vote per our bylaws. So I got that going for me.