LVG? I think its a safe bet that Holland can get to the semis, thats the 8th and 9th of July. It will take time for him to get out of Brazil, do a deal, take up the reigns... Last season started 18th Aug.
LVG's teams rarely started off with good results. He demands a style of play which isn't going to suit everyone and given there isn't really a strong 'core' XI at Spurs to begin with, I'd imagine it would take a while to figure out who can adapt and who can't (or won't).
It took him 3 seasons to build the title winning (and everything else winning) side at Ajax, 3 seasons to win the title with AZ (admitedly finishing 2nd in his first year) and even struggled in his first 6 months at Bayern before building the foundations of the side that is now dominant. He failed with Holland at his first attempt, and it's only Barcelona where you could say he had instant success.
If we got Van Gaal then I'd expect us to finish outside the top 4 next season but certainly show the kind of progress during the season that has been utterly missing in the last 2 seasons.