Some of us are attached to our team, legends past and present and history so for me, starting again is not an option.
I understand that and I don't mean to throw in the the garbage, only to put it in the freeze.
Wait 5-6 seasons in the same lv so some teams to promote and fill the upper levels.
Also you would face new opponents.

i know it is hard but Nordeus should figure this out playing without level like Asso Fa
very hard, almost rebuilding the game
Imagine that with the latest update (TE2018) which changed only the Team's secion, horizontal instead of vertical, we had so many bugs, some of them are still here (subs, F-K, C-K settings, wrong stats in stats-goals).

Merge servers
creating new servers for teams above lv 50 for example.
That looks good.