Why not delay the season? Its not fair to ask Donovan Smith and many other players in a similar situation to choose between their career and team and their families health and safety. Not if you can help it.
You could delay up to six weeks without too much difficulty in my opinion.
1) You could take away the bye week before the Superbowl. Save one week.
2) You could shorten to 14 games. Save 2 weeks. I doubt reducing the number of games is high on the list for the NFL but that option is there.
3) You could reduce a week because you are cutting back on preseason games.
3) You could push back up to 5 weeks and still not interfere with the NCAA basketball tournament, ending up with Superbowl Sunday and NCAA Selection Sunday on the same day.
I've posted previously how there are only three stadiums where it gets wicked cold: Green Bay, Chicago and Denver. So with about a month more of cold weather games you are looking at about 5 to 10 cold games in context of over 500 NFL games. NFL Stadiums now have heated fields and benches anyway.
The NFL still doesn't have things sorted out, and training camp is coming soon. Delaying the season six weeks would give the NFL the opportunity to get its act together. Perhaps the nation will be in a better place regarding Covid and treatments or vaccines. It will reduce the chance that they will have to shut down the season because of an increase in the virus.
And last but not least you are trying to at least delay putting the players in the position of having to make a very tough choice.