The Highland League has lost Inverness Caledonian, Inverness Thistle, Ross County and Elgin City (arguably their 4 biggest clubs when they left) and Peterhead, no lightweights themselves (in HL terms), and it has survived, thrived maybe. Granted there were no TV deals predicated (allegedly) on the big 2 meeting 4 times a season (for the "big two" perm any 2 from Caley/Thistle/City/County) so it's not exactly analogous, but Scottish football will survive.
I don't believe we are hurtling towards 5 teams going into admin "within the next couple of months". That would mean all 5 teams were in such a parlous financial state that they required to have a home game against (old) Rangers within 8 weeks of the season starting in order to benefit from their "massive" travelling support and so avoid admin. That just does not make sense.