I am British and wish to join my Chinese spouse in China. I have been advised to try for a Q1 type.

Hi, if you hold the Q1type, after entering China, you can apply for a residence permit which will allow you to stay in China for 1 year or more.
You can extend your residence permit at the exit and entry administration of the local PSB one month earlier before it expires. If it can be done, you don't need to go back to your home country.
First, you need to provide passport and its copy, a passport-style photo, a completed application form, residence permit in China, an invitation letter and your spouse'd ID card, as well as your marriage certificate. And then go to the exit and entry administration of the local PSB to extend it.