Seems like this is the only viable option. It fixes the OverflowError but comes at the cost of precision and time.
Another option would be to try/except the overflow error and only then return the slower method.
Regarding the data [8.988465674311579e+307, 8.98846567431158e+307], float has lesser precision than other types like Decimal so the patched method would return 8.98846567431158e+307.
A dataset to test the fix is [8.99e+307, 8.989e+307] which gives a correct result.