You talk of multiple options when in fact there are only three. The three are:
1) Cancel the Euros and finish the season by end of June.
2) Void the season.
3) Say the league is finished now.
Of all the options. Option 1 is of course the most desirable. However, there are questions over whether it will be possible. For it to be possible the following is going to have to happen: 1) Virus dies down by the end of April/early May and all teams do not have players out with the virus or in a bad way because of the virus, 2) Risk of players/staff contracting the virus is not likely if the games are played, 3) All competitions can be played and not just the leagues.
Option 3 is the least desirable. Too many teams would be completely screwed by the option. Relegation and European qualification is the most financially serious issues facing clubs. Changing rules as to when a season ends causes massive issues as teams would've had harder runs or games, less home games than others and teams still in Europe and in good positions may find themselves out of Europe altogether for next season. Further, players would be out of contract and you would need another window which would give some teams an advantage that should not exist.
Option 2 is the halfway house. If the season cannot be finished then that is a loss of 25% of one season. Completely re-jigging or cutting other seasons and competitions so that this one can be played out would lead to greater financial cost than cancelling this one.
So, all in all, the options are finish this season by end of June or void the season. Everything else is just unfair or requires the creation of new rules that benefit the minority rather than the majority.