After you get across northern MN, you might go south. Near Milbank, SD and Apelton, MN, you'll cross the continental divide. Not dramatic like the mountains but from there every thing flows north to Hudson's Bay or south to the Gulf of Mexico. Water...
Most times there is a sight glass in the liquid line. It should be clear. Clear would mean it's fully charged and all liquid is passing by or that is completely empty. If you see bubbles, it may need more Freon especially if it is nearly all bubbles....
Plenty of things to see and do in MN "fer sure". GS won't be bored with Sea Life Aquarium in MOA. And nearby is Water Park of America in Radisson hotel. Also, there is Valleyfair Amusement Park SW suburb of Shakopee. Duluth has transportation museum,...