You sound like an extremely strong cyclist, rebayona. I toured in Colombia in early 2019. I flew into Medellin and biked from a small town south of Medellin to Armenia (the town in Colombia, not the country obviously). I passed through Manizales on the west side of Alto de Letras, but never considered climbing the pass. In my younger days, I biked over lots of passes including at least one slightly higher than Alto de Letras, though starting at a higher altitude. You've got one big advantage living in high altitude Bogota at over 2640m (8661 ft). Fortunately, I've never experienced altitude sickness, but I live near sea level so I definitely could feel the altitude while biking and hiking in your beautiful country. On the way to Armenia, I met some British cyclists who were going to bike over La Linea east of Armenia, another high pass. They tried to convince me to join them, but I declined.