The first confirmed Overland trip to the North Pole was in 1968. It wasn't for lack of trying there were hundreds of expeditions. But dog sleds would hit open water. https://en.wikipedia.org/wiki/List_of_Arctic_expeditions
the early Antarctic explorers century ago were able to start their land voyage disembarking from ice cutters hundreds of miles further south than modern icebreakers can set expeditions now.
Given all the evidence (for example the thermometer placements) that the surface data and all the old data is bogus these results seem harder fake and thus pretty good evidence it may have been warmer and certainly wasn't much colder a century ago or more.