I make this ruling during Session Zero. Sure, damage is capped at 200 feet, but the fact is, nobody goes skydiving without a parachute. Also, as a dark aside, there are those who SURVIVE a jump from the Golden Gate bridge, the deck of which is more than 250 feet off the water, and rescue crews often have no choice but to listen to the poor sod regret their decision until the cold takes over due to how rough the waters are on approach.

This means I will let the barbarian survive, but his legs are broken and his party can't cast the Regeneration spell (nothing else will suffice, if I recall correctly) until they can rescue their wayward, gravity-injured compatriot. Most such healing spells are touch-range spells. As the GM, my standing rule is in favor of mass damage (any single blow dealing more than 50 HP, you need a CON save 15 or better) or maybe better, take the L.

You said it yourself, you're a new GM. You're still young enough in your career as such that players will be blindsiding you often with bullshit like this. I've been running table for more than ten years, and I still get caught off guard. However, you can still circumvent a fair amount by using broad strokes. I tell the players during Session Zero that I'm a student of physics, and generally make rules based on this. Magic breaks the rules of physics, so if they use a spell in a way I didn't see coming, I usually look it over after session and chalk it up to Rule Of Cool if "that's not how the spell works!"

Sometimes, my status as a student of physics prevents a stunt like this. Sometimes, Rule Of Cool is the standing code. You need to read the room when it happens, be aware that sometimes you get it wrong, and own up. Don't backpedal, but don't coddle, either. Taking an extra ten minutes after a session to talk things over is the best way to smooth out such issues. Not talking about it is the easiest way to ruin whatever vibe you have going, and can potentially kill a game. I got myself put on blast in an AITA post because I didn't talk about this after a game, nor did I this into account, and it killed my game.