We would be arriving guangzhou around 1AM local time.

Do you start from Baiyun Airport?
If yes, upon landing, you can take airport shuttle bus line 1, and go to Main Railway Station first. This bus line still operates till the arrival of the final flight. So you can catch it. It costs CNY 18 per person. After that, take a taxi to your hotel. The cab fare is CNY 20 to 30 at that time.

If you take the taxi from the airport directly, the cab fare is CNY 100 to 120 in the night.