Vision impairment/vitreous issues. how bad or big are floaters that require surgery?

Depends on symptoms: Floaters really don't require surgery. Surgery will be elective. Even modern 25 guage vitreous surgery is not without complications, however. There is still a 1% risk of retinal detachment and a very high likelihood of the development of cataracts. My own vitrectomy was not done until after my cataracts were removed in spite of a lifelong history of very bothersome floaters.

Depends : It all depends on how the floaters bother you and affect your activities of daily living. There is risk with any surgery, but if your symptoms are bad enough, consider vitrectomy (surgery) wait one year to see how the symptoms are before proceeding to surgery.