May has some rather vital legislation to get passed by parliament.
Stalling this helps no one. Delaying until January is not going to achieve anything useful, it merely enables Corbyn to call for a vote of no confidence in the government, and the outcome of that would be anybody's guess.
May's hubris may well lead to both her and her governments downfall.
She needs to go now, and I am sure many others view the situation the same way. Interesting times!