Not straight Postgres, but this dataset would be ideal for a columnstore index with compression - huge runs of the same value are readily compressed with run-le

Not straight Postgres, but this dataset would be ideal for a columnstore index with compression - huge runs of the same value are readily compressed with run-length encoding. Partition the whole thing by the status of the up flag, perhaps additionally by month, and the SELECTs can be pretty well optimized.