I think likely to be infinite, per Gödel's incompleteness theorems. Given a corpus of maths called A we can always find new unprovable axioms under A, giving us a new corpus. From there we can prove new theorems.
There may be a finite point at which we've proven and codified everything but the most inane meta-meta-meta-maths though.
There may be a finite point at which we've proven and codified everything but the most inane meta-meta-meta-maths though.