As an honours-graduate ATPL currently working as an FI and waiting for my first commercial job, I would honestly say that as far as my flying career is concerned my degree has been about as much use as a chocolate watch.
Sure, having a degree looks better on the CV, but I will echo what has been said above: do consider whether it is worth 3 (or in my case, 4) years of seniority and pay. When I was in my late teens, many of my friends went either direct-entry military, joined BA as cadets or embarked on careers as FIs, rather than go to uni. 15years later, all of them are now experienced jet aircrew, several of them captains. I, on the other hand, went direct-entry pilot in the RAF, binned it after a few months, then spent 4 years (standard in Scotland) at university, from which I graduated with an engineering degree. It has taken me a hell of a while to claw my way up the ladder to the present point where I'm flying as an FI, but consider myself to be 4 years older than I should be at this point! I originally decided to attend uni to have a 'second string to my bow', but now realise that this approach is pointless. As was mentioned, if your flying career goes tits-up for any reason you'll then have all the time in the world to go and get a degree afterwards.
A few other points; I found little advantage in the ATPL study in having a technical degree. University is great fun, but then again so is the social side of mil or airline flying. If you do attend uni then UAS is a Good Thing. Everyone I know that went through ELUAS at the time has gone on to much bigger things in either the RAF or civvy flying. As for me I couldn't get in having already VW'd from Cranditz at the old age of 21...
Finally, I would say that what seems to be a good degree choice at 17 or 18 may not seem so great 3 or 4 years later. A lot of people on my course were put off engineering for life by the end, and with hindsight wished they had spent a couple of years in the Real World first in order to have made a better informed choice. Good luck with whatever you do.