In theory yes, just need s3 fdw

I demonstrated this with ClickHouse: https://github.com/ClickHouse/pg_clickhouse/blob/main/doc/of...

We're working on a chdb based mechanism to copy to/from s3, maybe with fdw on top we can back table in s3

You can try similar things with pg_duckdb & pg_lake

No, and with timescaledb is a feature of their cloud platform. For on prem you can use something like Arc: https://github.com/Basekick-Labs/arc