My thoughts would be you should take it back to where you bought it, if the clutch is just slipping then you will be fine for that distance, i nursed a slipping clutch on my polo for 5 months(6000 miles). I’d be suprised if the dealer goes for fix it where you are as it seems driveable with care at the moment.
If you do not feel comfortable driving it take out AA or RAC cover that has onward travel/ transport to a garage of your choosing and do it that way.
Personally i would chalk this issue up to experiance and try and be better prepared in future if buying a car from a fair distance away. Depending on the price of the car i would concider the likes of a AA/RAC inspection prior to purchase so you can be better informed they are only £100.
I know what i have said is probably not what you want to hear and it does not take into concideration the loss of time you will incur but it is the fairest way for the garage to may right it’s mistake.