On 28 January, Wrangel marched with the cavalry out of Frederiksodde to Hejls close to Hejlsminde Bay, where the rest of the cavalry arrived on 29 January. They planned to start the ice march from a place between the villages of Anslet and Knudshöfft, south of Hejls. On 28 January, Charles X Gustav reached Haderslev and received reports from Wrangel about his route map. The king approved his plan, giving Wrangel permission to begin the march without the king and his troops, provided that the ice was deemed sufficiently thick. The king arrived at Hejls on 29 January: Wrangel had not yet set out. Later that day, a detachment of between 500 and 600 troops was sent across the ice to scout the road to Funen. The force reached the foreland of Iversnæs on the other side of the strait occupied by Danish troops. They had constructed two redoubts and additional fortifications and ordered Danish farmers to create a moat by tearing up the ice close to the shore. A strong current was discovered at the shore, creating a broken ice channel. The Danes spotted the Swedish force and bombarded it with their cannon. On the evening of 29 January, quartermaster general Erik Dahlbergh was dispatched to test the ice on the narrowest strait at Middelfart. During a nighttime observation, he found the ice sufficiently thick for an entire army to cross and raced back to the king with his report. But Charles X Gustav had already decided the army would cross the ice towards Iversnæs, ordering his troops to prepare to march the following morning. During the night, he dispatched troops to build bridges with boards and straw across weaker ice sections and gaps beyond Brandsø. Reconnaissance patrols were sent both north and south of Iversnæs to take measurements of the current. The Swedes planned to cross the ice in a relatively scattered formation, to minimize the risk of the ice breaking under them. This created a dilemma as the Danes on Funen could locate and strike the approaching Swedish isolated units quickly.