I had another thought.

I have small wool rugs under my dining room chairs. A good way to remove cat hair from them is to dampen a sponge and rub it over the rugs in a swirling motion. The moisture breaks the static-electricity bond, and the hair collects in long strands, which can be picked up and discarded.

You would need a partner to hold the blanket taut while doing this, but it's worth a try.

With the passage of years, I have gone to using a sponge mop, rather than a sponge, for this job. Easier on the back. The mop is never used for anything else.