Sorry, but your link did not bring up any pictures. Isn't something missing from the beginning of it?

all evergreen plants.. lose the older leaves on an annual basis ... some years worse than others ... and that usually happens in winter ... when light levels ebb ... i think.. one of your problems.. is that it has outgrown the window ... when it was much smaller... it got much more light on top of its leaves ... i dont have time to find you the latin name.. but i do know.. when you get it.. and google such.. there are millions of websites on how to propagate it [youtube also] ... as you are well aware.. its not that hard.. if the whole family has the plant ... and once you cut the trunk to say.. about 6 inches.. and propagate 20 or so plants from the trunk .. the part still in the pot ... will rebud lower down ... do not swamp it... over-watering it .... in winter ... it will be much worse.. if you rot off its roots... been there.. done that.. lol and no.. a stressed plant does not need to be fed ... perhaps in late spring would be better time for a bit of plant food ... ken ps: when you cut it back to 6 inches.. that would be a great time to get rid of all the old 'used up' media... and repot it ... potting media does not last forever ...

First of all I would contact USPS and have a word with them. There was no reason for them to leave plants outside when you were waiting at home, especially in these sub zero temperatures. As for the plants. I would give them a little recovery time. They are already stressed. Repotting them now will only add to that. Give your plants an chance to acclimate to their new environment. The opportunity to repot the plants will still be there in a week or two

Looks like sunburn to me. If they were inside and receiving not much light, a rather sudden increase, even if the lighting is indirect can cause sunburn. If the soil was on on dry side, it would make them even more prone to sun scald. Snake plants are one of the toughest indoor plants to be found. The damaged areas very unlikely to be fungal damage. You need a lots of humidity and little air movement for fungal problems to start. Snake plants have a very fibrous leaves with a heavy waxy coating that would make it hard for a fungal problem to take hold. The damaged areas may just turn dry or the the whole leaf may slowly fade away. As an ex professional plantscaper, when faced with a problem like this, the whole leaf would be removed with the cut being made at the soil line. Hope this helps.