Ric,
The information should be correct at the time the inventory was drawn up. Obviously it will often refer back to leases granted in the late 1790s or early 1800s but which still entitled the family to live there. Or if there was no lease it may say “at will.” Where a family had say a 3 lives lease, the inventory will often say who was still alive and what age they were. So that was contemporary information.
If you were buying a property today with a sitting tenant, you would want to know what the terms of that tenants lease said. What income would I get and what rights of tenure did they have? It was much the same with the Encumbered Estates sales. It enabled the potential buyer to decide what income they were likely to get, which properties had tenants with the right to reside indefinitely and those that were coming up for renewal, and those with no lease. (By the 1850s some farmers had the right to renew their leases ad infinitum, provided they paid the rent and otherwise complied with the terms of the lease). The sale of the property had little direct impact on the tenants who were simply about to acquire a new landlord. Their lease was unaffected.
As far as the famine is concerned, it’s probably worth mentioning that farmers in places like Co Down weren’t all that badly affected compared with the average Irish family, especially if they had a decent acreage. Whilst their potato crops were badly blighted, most farmers grew barley, oats and flax and that generally kept them going. (The price of barley and oats rose during the famine years so farmers in Co Down benefitted from that). It was the labourers and others with little or no land that suffered the worst in the famine. A labourer would just have a few perches of land, and so mostly grew only potatoes. (You can get more potatoes per acre than from any other crop. Handy if you have a large family to feed. Potatoes grow very well in the Irish soil (normally) and are not particularly labour intensive. You just put them and then leave them, so ideal for a labourer who would be away working. But if the potatoes failed they had nothing to fall back on, save weaving income, and were generally the worst hit in the famine. But they aren’t listed in the Encumbered Estates records because most didn’t lease directly from the superior landlord. They leased from the farmers.
I have attached a letter written by a farmer in the adjacent county of Antrim in 1848, in which he describes the impact of the blight, but you will also see that he mentions getting a good price for his oats and selling more than he bought and that as a result his family was fine. Farmers in Down with sufficient land would have fared similarly. (Many of the population did not but if your family are listed in the Encumbered Estates records then I assume they were farmers).
I have also attached a link to a document produced by Downpatrick Museum summarising aspects of the famine in Co Down.
http://freepages.rootsweb.com/~rosdavies/genealogy/WORDS/Famine.htm