Only being away for 10 days 2 or 3 times a year should be fine but you need to make sure they have a lot of food and water, especially in the summer. It would be much easier to give a friend a key to your flat/house and have them look after the rats while you are away! That way they get play time while you are gone as well!

They look lovely! Are you planning on getting a larger cage? That one looks quite small and rats love it when they have lots of room to move around.

From what I have seen online the critter nation cages are the best. It is quite expensive but it is definitely worth how much more happy your rats will be!