I've heard through the grapevine Timberline will remain closed for spring skiing until at least the end of May. They are however currently planning to open for summer operations, covid-19 permitting. One hiccup is the Palmer chair (the one used to get to the glacier) was badly damaged from an ice storm and needs a ton of repairs. I'm not certain if they can repair it during social distancing, but hopefully it's deemed essential work and gets fixed up. If all goes as planned Timberline will be open for summer shred.
And if you haven't seen yet check out timberlines website, they are no longer having private lane space at Tline for Windells, High Cascade, MHSSC etc. Instead Tline is running all parks as 'public' with a little paywall to get in. If this goes as planned summer skiing is going to be phenomenal this year, even for anyone not in a summer camp. Check the link below.
But, tragically, be prepared for the possibility of no skiing this summer. This whole global pandemic thing is a bitch.