“How close can you fly something to the roof?”
Not very, at least not for more than a second or two. Any spell effect would become unstable well before approaching the roof itself. So I wouldn’t be able to maintain, say, a Lightweight spell. If I tried, it could cause unpredictable effects.
You figured it wouldn’t be that easy.
“But what if you could lighten me, launch me into the air with a catapult, and then return me to normal weight?” you ask.
You’d come down unpleasantly fast and I’d have no idea how to calculate the trajectory, the wizard replies. She sounds a little annoyed even though her mental voice has no actual tone to it. Maybe it could work if you had some kind of glider to slow your descent and control the landing yourself. Personally, I’d look for a ladder.
“I don’t know that they make ladders that tall,” you say, looking up. “Wonder why they made this place so big. Anyway, I think I can rig something together.”
You quickly find what you need to launch yourself – a board and a big rock are enough if you can balance the board on something. But you’ll still need something to help you glide once you’re in the air.
Your robe will have to do
Cut two sticks of the same size, and tie a huge leaf to them, you grab the sticks and the leaf softens your fall
You’re an expert at pirouettes, if the wizard makes you spin fast enough, you’ll descend slower, like Mario twirling in the air
Attach something soft to one end of a pole, you land while planting the soft end on the roof floor, and the pole bends, lessening the impact of your fall