Any recommendations to help my poor old knees

[Eve]

Skiing next week for 1st time in years and know my knees will feel it.

Do yoga & HIT regularly , hoping that is some help.

Would knee supports help at all?

If you are a keen skier or planning to continue skiing for a number of years to come, might be worth investigating a Ski-Mojo? Can't do links but have a look on Google.

Yes. Knee supports help a lot.
Pull on neoprene ones are good and the ones with Velcro straps are even better.