I see two possibilities:
1: They try to keep up the energy kick and scream bloody murder at every turn, but never achieve anything, as they have exactly zero leverage to affect anything in Westminster. They fizzle out, and nothing much happens and things return to normal. Their big shot, independence referendum, has been fired and can't credibly be reloaded and re-fired anytime soon. Even Nicola Sturgeon admits this.
2: They get down to business and negotiates as a serious counterpart for actual regional political influence. This means getting their hands dirty on actual politics and compromise and at least toning down the Tory-hate-rhetorics, which could prove a very bitter pill to swallow for their base. See: Liberal Democrats, 2010-2015.