What do you have, a single cable-type headstay, an overlapping
jib, and a "working
jib" or something smaller for heavy air?
And reefing a reefable
jib is, for you, the equivalent of changing
jibs, meaning stowing the old one, and breaking out, hanking on, sheeting, and raising the new one.
Definitely doable, but takes time and physical effort, while someone, or some device, holds course, probably on a close reach.
In "just" a summer squall (not a weather front), and no close lee shore, you could just drop your
jib (and yes a downhaul would help) and ride it out with reefed main, or even luffing main if you got caught without enough time. Five minutes later you'd have nice weather.
But if it's steadily worsening conditions, you've reefed main, you have to reduce
jib size to keep her balanced, then you've got a challenging piece of work to do alone up forward.
Definitely doable, but if you knew the forecast and had access to a crew when you departed, you'd really be grateful during this sail change. Reducing or changing out sails in truly snotty weather is why we have crews anyway.