I ended up backpacking through most of Europe this time last year and it was a truly amazing experience. One thing that my dad kept reminding me is "You know, Europe's not another planet...", and this eased my anxiety about it. Even though I wasn't diagnosed at the time, I was still extremely cautious of what I was eating.
I'm not sure where you are staying, but there are mini marts with basic necessities (like an upper scale 7-11) that will have food, snacks, and produce, but the grocery stores essentially like ours. You won't have a hard time finding anything that you wouldn't find here. Again, even though I wasn't diagnosed at the time of my travels, I was still able to buy things like wheat bread, nutella, peanut butter, things that have carbs and protein in them. Basically, I would suggest if you know how to treat yourself when eating things like peanut butter and crackers, for instance, this would be less of a struggle for you.
I went to both Prague and Budapest on my travels. Prague is becoming more Westernized but their dishes (at restaurants) still have European flair. There isn't an indulgence in fast food in these places, but it's always a good idea to know where the closest McDonalds is just in case. Plus, you're money will go further in Prague and Budapest as well with the exchange rates. A loaf of bread is about 50 cents USD and Nutella just under a buck. In Prague, and I'm not sure about Budapest, there is a chain grocery store called Billa that I did most of my shopping at. But they don't give you plastic bags, so bring a backpack =)
Because Czech and Hungary are sticky languages, some of the packaging will probably be in English or German, the more "popular" languages in Europe, to make it easy for shopping.
The Hungarians are HUGE on soups, stews, lentils, and paprika. Since you're traveling in February (I went in November when I was there), you'll probably end up eating really hearty meals, but they might not be as carb friendly. Like someone else in this thread, I'd do some pre-trip insulin amounts. For instance, I know that I have to take 3 units if I eat waffles with peanut butter and a little bit of sugar free syrup. Doing some mental math like that will probably be helpful. Hungarians are more likely to use English in places of business, so I'm not sure that "what are the total amount of carbs in this meal" will translate super effectively. But eye ball it. You'll also find a fair amount of international foods there that aren't indigeoness (sp?). Kebabs are everywhere. You can't go a block without finding a kebab stand. Kebabs will provide a great amount of protein and the pita it's on will probably be your only carb in take. On the paprika note, the Hungarians are crazy about their spices, but I have yet to encounter a spice that effects my blood sugar.
But I would check on the translation of carb before you go, just to be sure. Again, Europe isn't in a far off galaxy with no food
One last thing - make sure your husband (and you, for that matter) should definitely carry some type of identification labeling you as Type 1. Whether it's a medical ID bracelet or a card in your passport or wallet, make sure to do this. Also, let your trip organizers know with Contiki, or whoever, because since they're travel savvy, I'm assuming they've gotten into sticky situations, and they're going to be more than helpful with anything that may come up. So just give them a quick heads up, but stay positive and enjoy your trip. It sounds like a blast!
If you'd like any more information on Prague and Budapest, message me!