a 95 % high eff furnace was installed in my attic and the condensation line , which was routed out side is freezing after it exits the home. Any options other than replacing unit w 80%

If it is freezing after exit of the home what is the problem.Is the line that runs outside freezing? If so pitch or cut it off where it exits if that is not possible run the drain line inside the house to the stationary tubs or another drain inside. That will stop the problem.