The Us, the lowest ranked side remaining in the competition, held 11-time FA Cup winners Manchester United to a goalless draw last Friday at the R Costings Abbey Stadium to earn a glamour return at Old Trafford on February 4.
"There's a lot of speculation about how much money the club will be getting but it certainly looks like it's going to be in excess of Â£1.5 million," Doggett told ITV.
"Hopefully we can get the stadium done and start putting in some proper toilets
Some toilets and tea bars and more hospitality..
that's what we will do."
Cambridge returned to the Football League this season after a nine-year absence and flirting with financial oblivion.
Richard Money's side twice won at Wembley last season - the FA Trophy final and promotion play-off from the Conference - and the cash boost from going to Old Trafford eclipses their annual wage bill, which is around Â£1.1m.
"We obviously need to take stock of where we are but our ambition for some time now has been to improve the stadium," Doggett added.
"It needs modernising and the facilities need to be fit-for-purpose, and I think it's fair to say Friday's performance has been a game changer for the club.
"It's certainly a far cry from the situation we found ourselves in a few years ago, where we were reporting losses of around Â£400,000."
Cambridge must refocus on the League Two campaign for now, with matches on Tuesday against Dagenham and Redbridge and on Saturday at rivals Luton, whom they beat in the FA Cup third round to earn the Manchester United tie.
Source : PA