I don't see Alexei as living very long, certainly not in good health. When I was training as a solicitor I got involved in the litigation over British haemophiliacs being infected with HIV through contminated blood products. Part of my role was to work my way through the medical records of about 40 haemophiliacs, most of whom had been adult by the time effective treatment became available. Most of them were increasingly crippled by the destruction of their knee and hip joints caused by severe bleeds in boyhood. Bear in mind that over three months after the bleed in Tobolsk Alexei was still unable to walk a step. We can mention Waldemar of Prussia, but perhaps he was simply a much quieter person who didn't injure himself so often. Leopold of Albany was quite an intellectual, keen on books and music.
I fear that Alexei would have been in a wheelchair by the time he was 30, or, alternatively, would have been one more haemophiliac prince killed in a car accident between the wars.
Ann