Welcome to cruise-chat! Europe is no longer a bargain no matter how you do it. The dollar is quite weak against the Euro and just doesn't go far. There will be many outside tour options and winging it is always an option. You want to do some heavy research before attempting to wing it or even choose an outside the cruiseline option. There are many far more knowledgable people on here than I when it comes to Europe and I hope they'll give you their take based on their experiences there. In the meantime, there are a great deal of previous posts that are related to your question from previous posts. You may want to click on the "Find tab" with the little hour glass and type in a few keywords like the names of your ports to see what has been recently discussed on the topic.