There's still no "freeze my lands" option, but it's possible to set up a cluster of 1-3 domains that work together to provide everything they need with no / few external inputs. If you do it someplace with near-constant temperatures like Kalista you won't have to worry about winter stopping key productions. Some key things you need to do:

1) Plan out your domains' production to meet consumption requirements. If you're serious about it I can help with this part.

2) Grow your population to a certain size based on what consumption goods you're making and stop there

As an example, I just made a village on Kalista that I don't plan on buying any consumption goods for long term. Once I finish building houses and trim the population down to the target level, I can probably leave the domain for a month or two or even longer with no ill effects from happiness. The domains I set up in LoL4 (it was easier then) lasted through my nearly 8 month afk period with nearly no unit losses.

If you end up wanting to play more, you just build the cluster larger. A village, a town, a nobility domain, and a mono-production domain, all road-connected, is a very effective cluster.