"add hugely" is correct and can be used in written English.
You can use it to emphasize the amount of something that is being added. For example, "We added hugely to our customer base this quarter."
And the G.O.P. plan would add hugely to the deficit — about $700 billion over the next decade — while doing little to help the economy.
That's unless, of course, Mr. Bush — or Hillary or Mitt or Rudy or Barack after him — add hugely to the national debt.
The Iraq war logs add hugely to the evidence in the public domain about the number of Iraqi civilians killed during the occupation.
As our Fair Fares Now campaign has pointed out, this will add hugely to costs for hard-working families, and contrasts with the government's willingness to stop fuel duty increases.
These are the kind of stories that, while they add hugely to the enjoyment of reading The Histories, have resulted in a long tradition of dismissing Herodotus as gullible at best, and at worst a liar.
This will add hugely to the burden on governments to provide education and essential services.
Its infrastructure is poor, adding hugely to production costs.
This adds hugely to the cost, and deters many.
The Tories failure to cohere round a line of opposition adds hugely to Mr Blair's room for manoeuvre.
On the whole, everyone seems to be happy and buzzing, which adds hugely to the entire university experience.
That has made suppression all the more difficult and dangerous, and added hugely to the cost of containment.
