Certified GKH Gardening Expert
I am sorry to hear about your plants. The cold has damaged many plants this year. You will need to remove the yellow and brown fronds this spring as they will not come back. Just use sharp shears to do so. Do not remove green parts of fronds. These articles will help you as well:
It is hard to say how well they will grow back. Sago palms do not deal well with lost fronds, but they have been known to recover fine. I would wait a whole season to see if fronds grow back.