What a great trip! The itinerary, the guides and the fellow explorers created a brilliant trip.
The ice cave on the first day is an amazing experience and gives you a chance to see how your clothing choice works. If you are claustrophobic you may need to be brave - the entry is narrow and steep (with a rope handrail), and inside the caves you need to move on hands and knees in some places due to low headroom.
The three day trek is core to the trip and was a unique adventure. The pace is easy and you cover about six miles each day with plenty of stops. The sleds slide easily but do require some effort on the uphill sections.
The communal tent and toilet tent are already set up at the camp site and you bring your sleeping tent, sleeping bag and personal clothing in a kit bag (or dry bag) on the sled. On the middle day you need a small/mid size back pack as the tents and sleds stay in place.
You will see snowmobilers, skiers, dog sleds and other groups in the distance on occasions.
Breakfast is a variety of breads, cereals, tea and coffee, lunch is a freeze dried meal and diner is cooked by the two guides that accompany you (typically a Reindeer stew or similar). I took a few snack bars, but didn't need all of them as the food provided was fine.
Your one hour polar bear watch during the night fly's by, at this time of year it does not get completely dark, just twilight and the scenery is bathed in a magical light.
For me the most challenging thing was the general dampness - whilst you are warm while you are moving, you will cool down in camp, so fresh clothing is important. The communal tent has a fire and got up to 20 centigrade, but frost forms on the inside of the sleeping tents and if you brush it with your head, it falls on you and your sleeping bag which adds to the general dampness. You typically keep a few layers on in your sleeping bag, and I had a balaclava plus a woolly hat. For our week, the temperature was around -12 centigrade, but any wind makes it feel noticeably colder, the Norwegian weather website yr. no is really useful.
The snowmobiling on the last day was a fun way to finish the trip. It was surprisingly intense as the established tracks you drive on are rutted and bumpy in places. You can always go pillion if you do not want to drive - but you will miss out on the fun of driving.
The guides were different for each of the activities, but were all excellent.
When we were in Longyearbyrn the group generally ate out together in the evening, as there are plenty of restaurants to choose from. The accommodation is a hostel rather than a hotel (no en-suite), but no worse for that.
All in all, it was a great trip with lots of incredible memories.