If I am Hamas, I will go 3D, so it give the Israeli something else to worry about. 3D mean you fought Israeli laterally, from underground and from above ground. But then whoever above ground would most likely not going to come out alive,.
Long story short, you can't depends on tanks in Gaza, some places maybe but most are too build up to use tank, which mean if I position my people on both on top of building (or at elevation in our lingo) as well as fighting Israeli at ground floor and underground using tunnel, that would make a lot of trouble for infantry intensive battle like the one Israeli is going to raise. Because you keep them scanning all around, and that either slow down the incoming troop or make it a complicated battle. and slow and urban warfare do not mix.......
But in all, I don't really think HAMAS can defeat that strike if the Israeli are determined to win, because Hamas is going to be outnumber 20-1 to 30-1 depends on Hamas number (It was estimated between 10k to 20k) The best strategy for Hamas is to make Israeli bleed, the problem is, with Israeli Air Power and Artillery power, Hamas will be left with a dilemma to whether try to ambush Israel everywhere or pick a concentrated spot for better chance, because if they are too dispersed, it wouldn't maximize damaged done to the attacker, but if you are too concentrate, then it will give the attacker chance to soften you up with direct/indirect support. Another moral dilemma is to whether to use Palestinian civvies for the fight, usually problem with this is this is more or less a point where you basically dare the Israeli to shoot at untrained civilian, make it nasty, But I am not too sure will this work with this Israeli force.