KTM-CTU-SFO eligible to stay at hotel outside airport

If your layover in Chengdu is less than 24 hours long, you will be eligible for 24 hour visa transit and if your layover is longer that 24 hours for just a minute, you will be eligible for 144 hour visa free transit. Now, you know, the length of your layover.

So, I will assume that you will have a layover shorter than 24 hours. In this case, you will approach 24 hour visa free transit counter upon your landing in Chengdu and you will apply for a temporary entry permit (this is not a visa). Since your layover is during the night, you are advised to book your accommodation in advance and to have a confirmation in hard copy with you. You will enclose your confirmation and your chance to be granted a permit is very good. Anyway, you should always have in mind that when flying on 24 hour visa free transit, the issuing of a permit is always upon sovereign discretion of immigration authorities.