Coming from Mýrdalsjökull ice cap. Sólheimajökull is about 60km long and 1-2 km wide. The glacier has changed a lot over the last few years and is changing very fast. It is possible to book a variety of activity around the glacier such as glacier walk and kayaking on the recently formed glacier lake. Sólheimajökull is though not the place I would recommend doing these activities, especially not if you plan to go to Skaftafell or even further there you will find bigger and less crowded glaciers for similar tours.