We visited Kiev for Eurovision Song Contest in May 2017. It was 5 years after our previous visit and we noticed immediately that the city has developed much. We do recommend you to consider Ukraine as your next destination.
Do you know that there won't anymore be mobile roaming charges in the EU area in 15th June. Not all pre-paid subscriptions are functioning abroad so it could be time to consider post paid subscription now. Overall, they can also become cheaper for you.