I have put a reply here on this specific topic, as in tips for artanis on dead of night, the rest of the thread may be useful as well.
To add to my reply, a few cannons can help hold the early nights specially if they are in tandem with your allies defenses. Keep in mind though any amount spent on cannons is potentially less on army which is ultimately what you need for finishing this map, and it will hurt you as artanis to not spend it on army instead.
While I list zealot goon archon as the ideal scenario, for reasons that archons can easily clear waves and the dps is more optimal for destroying the buildings, this composition is at least sub par for defending if you dont make good use of storms or zealot aoe. Zealots warped in waves can help to clear masses of infested while you are defending but you will ultimately lose these and dragoons are very prone to dying as well. Immortals will surely help you to have a more effective defensive army on this map if it comes down to that being required.