I'm sure you're already familiar with the uselessness of even trying to jump when flight exists and is far superior, and this is extremely situational at its best and completely useless at its worst, but it's still hilarious to consider a Warlock rabbit being able to jump 90 feet (about 27 metres) straight up into the air. Normally a high jump is limited to a number of feet equal to 3 + your Strength modifier, and that's if you move at least 10 feet on foot immediately before the jump. So how the heck did I get 180 feet? Allow me to explain.

Rabbit Hop allows a Harengon character to jump a number of feet equal to five times their proficiency bonus as a bonus action without provoking opportunity attacks. Opportunity attack evasion is nice, but the key focus here is this allows a PC with a maxed proficiency bonus (+6) to jump 30 feet either straight up or as a distance, and it's straight up I'm interested in. Next, we have the Otherworldly Leap Eldritch Invocation, and you can already see where this dumb shit science is going. This allows a player to cast Jump (which triples your jumping distance by the way) without a spell slot or material components.

30 x 3 = 90, therefore you could jump 90 feet straight up into the air. The best part is that the jump height doesn't even count as player movement, so you can do this regardless of your movement speed as long as it isn't already at 0. As I mentioned earlier, flight is far superior to jumping in just about every situation, but think of this: you get your wizard friend to cast Feather Falling on you as a reaction. Feather Falling slows the rate of falling to 10 feet per round with no acceleration. To put that into perspective, you're falling 1.6 repeater feet every second (about 0.5 metres per second). Best of all, Jump requires no concentration to sustain its effects, so while you take about 9 rounds to float safely back down to Earth, you can pepper your opponents with Cantrips and random crap from the relative safety of the sky.

Would this be more viable with someone who's not a Warlock? Yeah, a Wizard would be a much better choice for damage output, but I assume none of you want to waste a 1st Level spell slot on Jump, so that's why I went with the Warlock. So, there you have it. The dumbest idea my sleep deprived brain could come up with at this time of night: a Warlock with extra springy shoes and potentially a Wizard friend kind enough to cast Feather Fall to entertain their bullshittery. Do what you will with this information.

And of course, as soon as I post this, I remember the Updraft option of Control Winds (5th Level Transmutation, Tasha's Cauldron of Everything). 

Updraft. You cause a sustained updraft within the cube, rising upward from the cube's bottom side. Creatures that end a fall within the cube take only half damage from the fall. When a creature in the cube makes a vertical jump, the creature can jump up to 10 feet higher than normal. 

Depending on if your DM's willing to entertain the 10 feet bonus as a part of the initial jump or not, then you could either jump 100 feet (about 30.5 metres) for a no-go on the bonus, but if they allow you to count it as part of the initial jump, you could get up to 120 feet in the air (about 36 metres). 

You might want to re-read Featherfall.  You descend at 60ft per round (which is 10ft per second), so you'd only be in the air one round before you land even at your maximum height of 90ft.

Choose up to five falling creatures within range. A falling creature’s rate of descent slows to 60 feet per round until the spell ends. If the creature lands before the spell ends, it takes no falling damage and can land on its feet, and the spell ends for that creature.

Thanks for picking up on that and correcting me, mate. At least it means being stupid still won't instantly kill me. Note the instantly bit, because there's a very likely chance I'll still find some really stupid way to abuse this and either annoy or amuse the DM. Maybe if I position myself over an enemy and then if I took damage, I use Tomb of Levistus as a reaction, basically dropping a Warlock-sized block of ice onto their heads...

Quote from Sirocco745 >>

Thanks for picking up on that and correcting me, mate. At least it means being stupid still won't instantly kill me. Note the instantly bit, because there's a very likely chance I'll still find some really stupid way to abuse this and either annoy or amuse the DM. Maybe if I position myself over an enemy and then if I took damage, I use Tomb of Levistus as a reaction, basically dropping a Warlock-sized block of ice onto their heads...

 A similar tactic you could also use would be a Hadozee Swashbuckler if there are things to climb (like you're in a forest, or on a ship with masts).  You could drop on an enemy, likely knocking them prone, taking no damage, make your attacks at advantage for sneak attack damage, then scurry up out of reach with your full movement without provoking attacks of opportunity.  Since you're using a Reaction to get to them... not your movement, you can move your full speed to get away from them, and since they'd have to use half of their movement to stand up, even a Monk isn't likely to catch up to you.

This is literally the first DnD character I designed!

Throw in some monk for the better jumps and the cut on the fall damage?