Suggested itinerary for a week in Wenzhou over Chinese New Year. Accommodation availability?

You can arrange the 7 days tour in the following way.
Day 1:Baizhangji Waterfall & Flying Cloud Lake
Day 2:Nanxi River
Day 3:Jiangxinyu Island
Day 4:Wuyanling National Nature Reserve
Day 5:Yandang Mountain
Day 6:Lishui Ancient Street
Day 7:Phoenix Mountain
In addition, there are still many hotels that open for tourists at that time. Don't worry. You are suggested to stay at nearby Main Railway Station. The surrounding transportation is convenient. Dongou Hotel is a good choice. The price is about CNY 250 per night. It's located at Dongjian Building, Wenzhou Street. Hope you like.

Thank you for the reply. So all of the places can be visited as day trips from the city? I assumed that I would have to stay overnight in some of the further away areas.

Yes, you can tour around most of them for one-day round trip. But it's ok for you to stay overnight to enjoy local custom and foods. It's up to you. Have fun!