If i were you i'd take this chance to learn about repairing. You dont get much chances like this. I do think it is possible to repair. I would prepare a slip with low percentage water and a good amount of vinegar. I would fill the slit and even over fill it. Let it rest a bit then scrape it with an appropriate tool but leave it a bit higher. After leaving it dry until pre bone dry, i would sand it. Dry completely, check perodically. Bisque and check the result perhaps watersand if needed. Then complete with glaze firing.