I'm ready to give up on this huge rose bush. I have lived here a couple years and only seen a few flowers, because it is more like a tree and has a million criss crossing canes that weave along its "trunk" and then the big poof of leaves and green canes at the top. It's covering an ugly metal pole along my driveway so I hesitate just to hack it to the ground.
But the problem pruning it is that I can cut a cane I know should go, but then there is no way I can pull it out from the bush -- way too tangled. Do you have any suggestions? I'm pretty new to roses. Should I just cut it to the top of this metal pole (maybe 5 ft high) and then try to start over?

But I can tell you from experience that trying to pull a long cane out of a large shrub is dangerous - for you! What you do instead is find the cane you want to remove and cut it back in small sections and it will be much easier to untangle and remove, say 1 ft. chunks (or maybe 2 ft if there aren't any laterals woven in among other canes.) But make sure you have on your gloves, long sleeved shirt and safety glasses!
You may look at this as a longer than one afternoon project. Cut a cane or two into pieces and get them out of the way and take a break, studying the whole shrub and looking to see what should come out next. Take it a little at a time and you'll soon have it shaped up to your satisfaction.

When I have to prune the big roses I do what Anne suggests. I cut it out in sections a foot or so at a time. You really don't want to just pull on the canes anyway. Besides it being very dangerous for you it will also do a great deal of damage to the remaining canes as you pull the cut one out. And you'll have to cut off the laterals as you go and remove them too.

I also suggest you start at the top and work down if possible as buford said. I've often thought a cane at the base looked totally dead only to find out when i reached the top that it wasn't dead at all but full of green leaf buds ready to sprout. Old canes can get that woody dark brown bark but that doesn't mean the cane is dead.

And it looks like it is fighting with the ivy at the bottom, that might take away some of the water/fertilizer for the plant.

Are those white flowers tinted pink? Kind of looks like Cecil Brunner. If it was my bush and it got some more light, I would be tempted to run wire from one metal post to the next on either side at a couple of heights and start training her horizontally to cover the fence. I would leave the last canes near the top of the fence since she already likes it there.

But if it is a Cecil or Lady Banks, I would probably wait until after it blooms in the spring.