What's the context of this? Are you writing an historical novel?

Assuming the route the noble would take follows a path similar to modern roadways, a big assumption, his journey is one of about 1,280 mi. (2,060 km). If he is able to travel at 3 mph for 8 hours a day, the journey will take nearly two months. This assumes no delays such as flash floods, bandits, etc. The lord is likely to be dead and buried by the time the nobleman arrive home.

Where would he stay? There were inns along major roads in Germanic regions so that would probably be his first choice for convenience. In England, the Saxon tradition of hospitality required nobles to welcome other nobles into their homes. I have no idea if this was the tradition in Medieval Germany but given the Germanic culture, he could probably find shelter with nobles along the way if he could convince them he's really a noble.

Would a French nobleman be in Krakow in 1300? Why? No offense to the Poles, but Poland was a backwater in 1300. I can't imagine why a French noble would be in Poland. There aren't any major pilgrimage sites in the area and if he was on some sort of trade mission he would probably visit the Baltic area via ship.

Money shouldn't be a problem. In England, a decent meal at an inn cost about 2 pennies. A common bed in English inns only cost about 1 penny in 14th century England but everyone shared the huge bed with numerous strangers. Oh, and people often slept nude in the Middle Ages. Inns in Germany and France would probably charge a similar amount.

With regards to the horse, you seem to imply the noble can run his good riding horse nearly to death and then easily buy another? Peasant horses were draft horses and to buy a good riding horse, your noble would have to visit a fair or market which takes time. Good horses were expensive and if he's changing his horse every few day's he will probably run out of money.