Educational advice

I’m currently a 1st year Economics and Finance Student at The University of Reading. I’ve got an offer from Durham to study Economics with management, I’m in a bit of a predicament. At Reading I’m currently working at a 1st with average of 71% and i enjoy the course however going to Durham I’m not sure if I’ll be able to maintain my 1st class grade due to the course at Durham being more maths intensive as well as being more written exams and in person exams. At Reading a majority of my exams were half in person and half courseworks/online assessments  and multiple choice which is why i did well. I did better on the courseworks/online assessments compared and multiple choice when compared to the in person tests. Adding onto this, at Reading I spent majority of the day within the library studying for these exams so how could I possibly spend more hours in the library studying at a more intensive course? Furthermore, I was wondering if it was really worth redoing another year for the benefit of University name/better network/access to those high roles such as asset management. My short term goals would be maintaining the 1st as well as being able to get those spring weeks and summer internships. My long term goal would be job stability and being able to secure a high paying stable job when i graduate. Durham is a great opportunity but are all these risks a downside? Any opinions would be greatly appreciated.