Head gasket or lower intake gasket on 98 Blazer

I have a 98 Chevy Blazer 4.3 v6 Vortec. I had water as coolant instead of anti-freeze (yeah - I know now). Virginia got an unexpected freeze, and the radiator became a block of ice. I didn't know - started the truck, and headed down the road. When the temp started to rise (near red line, but never on or above redline) I pulled over, pulled radiator cap and saw ice! I let it sit for a while, cooling down, and hoping the overheating would melt the ice in the radiator. During drive back home, I had to pull over twice as temp started to near red. There must have been pressure because the lower radiator hose popped off. A few days later,I replaced a leaky freeze plug (had already been leaky - but the cold made it worse). Now the engine will hold water (no leaking out any freeze plug or anywhere else), but when I start it - white smoke/steam comes out of the exhaust. When coolant runs low, no more smoke. So I know that somewhere in the engine, coolant is being turned into steam. I plan to replace the lower intake gasket (had slight leak before the cold), but I don't know if it will solve the coolant problem. I don't want to replace the intake gasket, rebuild, and find out it's still burning coolant. How likely is it that it's only the intake gasket, or how likely that it's a head gasket. Trucks started fine, didn't seem to be 'missing'. Does this sound like a head gasket problem? Also, if I am to replace the head gasket, can I remove the head without removing the exhaust manifold (obviously Id have to disconnect it from the exhaust pipe before the Y). I'm afraid of the exhaust manifold bolt snapping off. Thanks in advance!!