Pwn Challenge Old Bridge

I am kind of stuck with this challenge, quite a hard one with respect to what I could be used to. I found an old post about this challenge, but it seems that no one will answer there, so I created this new one.
I understood how to obtain the canary and also what will be the aim of my ROP chain (I’m trying not to give away anything, it’s hard to write without spoilers), but the problem remains the limited space for my gadgets.
Speaking of gadgets, I cannot find any that could solve this problem about not enough space. Could anyone try to help me? I do not want the solution of course, just some useful tips.
I’d be very grateful.