Why is my Postgres / ADO / VBA text field being truncated?
It's all in the Connection String.
First, connection string extended properties as mentioned in the question have to do with reading Excel tables with ADO and are not relevant for Postgres.
However, additional parameters for longer text field sizes are available.
connString = "Driver={PostgreSQL UNICODE};Server=123.456.789.010;Database=cowbell;UID=charlotte;Pwd=spider;MaxVarcharSize=1000000;"
Fields in the sample table are all varchar.
More info here: https://github.com/ClickHouse/ClickHouse/issues/9363