The spikes were taking my noise margin from around 7/8 to 0 so i wouldn't know exactly how strong they are.
Then you would have to set your noise margin to 13-14dbs to cover the drop. If it still dropped, you would have to increase it further. You could end up with virtually no speed.

Many of the Sky routers will hold the connection down to almost zero, but with the noise margin so low, the connection would crawl due to errors being connected.

You would be better to try to find out what is causing the drop rather than just mask its effect.