Loved our week long adventure in Lapland, last winter.
We wanted to take the kids to see Santa but we got to do a lot more things there. The wilderness is amazing. Everything around you is frozen and the twilight light makes everything look beautiful. The temperatures are pretty low at -24C but it's bearable dry cold.
Our kids loved it too. We took a few reindeer sleigh rides and a wilderness safari looking for the Northern Lights. Sadly we did not get to see them due to overcast. It was snowing pretty much the whole time we were there.
The weirdest thing was the almost perpetual darkness. Only a couple of hours of daytime each day.