"it's fine if they're dormant"

Then store in the dark for two months.

Personally, I would want to prevent leaf senescence at minimal electric cost. Light at 660 nm is ideal for this purpose because it maximally increases active phytochrome (Pfr). I suspect that a minimum of 2 watts (actual power consumption) of 660 nm LED lighting per square foot, 24 hours/day might prevent senescence. Also, avoid far red light > 700 nm, which is prevalent in LED bulbs for household lighting and incandescent bulbs. There are inexpensive hormonal sprays that might prevent leaf senescence but that would be even more experimental. If you want to experiment with that, let me know.

Thank you for the reply! I'm obviously fairly new to this and clearly there's a lot to learn. Let's say I went with more lighting (or whichever process to prevent leaf senescence), how does that affect plants like annuals or herbaceous perennials which have a natural cycle? Is this process only good for evergreens? A daylight timer (timer which matches the daylight cycle) might be handy for this? Thx again.

With enough lighting and a timer to match daylight cycle, a plant will behave almost as though it were inside a greenhouse. For a specific plant, you should ask someone with experience growing that plant inside a greenhouse because I can't predict its behavior without actually trying it. As I said before, at low light levels, based on theory, 660 nm and 24 hours/day should be optimal for preventing leaf senescence.