Is there taxi available at taxi stand past midnight at Shanghai Pudong Airport at 1am?

Yeap. You can take taxi at 01:00 at the taxi stand. The taxi fare is around CNY210-230 at that time.
Besides, you can take airport shuttle bus night line to East Yan'an Road Middle Zhejiang Road Bus Stop, which is only about 1.2 miles (2 kilometers) from your hotel. The ticket fare is about CNY20. Then, you can take a taxi to your hotel at the cost of about CNY20.
You can choose the way you like.