Link didn't stop advancing upstream.
For this extracurricular practice activity, he opted to proceed as usual rather than asking for Sandra's assistance, fully prepared for the possibility that his every move and action could be under surveillance.
Within the academy, quite a few were aware that he possessed a "Small World".
Hesitating to use his "Small Word" when encountering troubles during the extracurricular practice activity would raise suspicions.
It was better to act as naturally as possible.
So, when he encountered the Giant Flame Salamander blocking his path and the Fire Elemental Elf whose surface temperature could easily melt iron and gold, Link employed his "Small World" to relocate them.
The whole process seemed effortless, as if it posed no challenge at all.
This was a testament to the immense power of a wizard who controlled a "Small World".