It might scallop your tire a little bit...I wouldn't worry about it too much. But do get it changed when you can afford it.

Don't stress on it too much. And get them done when you can. Don't ignore other needed service in the meantime. Oil changes, etc

It will cause your tire to bounce and wear a serrated edge on one side. It will cause you to lose traction and can easily cause you to wreck your car. It will cause metal fatigue in the spring and may eventually cause it to snap, especially in certain models. Ford Windstar had spring problems anyway, so I definitely wouldn't want a leaking strut on one of them. My husband's old Celica broke both springs and ending up riding on the tires. You can buy a little time, but definitely don't exceed the speed limit like that. You can lose control over rough pavement and hydroplane very easily in rain. Don't replace just one strut either. Replace both on that axle at the very least. Having one strut stiffer than the other can cause problems too.

I've blown suspension parts on a few cars and all I can say it "It depends" My Subaru used to have air suspension and when one of those struts started to leak, it was about three weeks before it went totally. Unfortunately for me, that disabled the ENTIRE suspension system and I wound up riding around all winter riding the bumpstops. VERY dangerous!!! Between babying it, often driving half the speed limit and swerving to avoid frost heaves and other road damage (NH Rt 10 mostly) and a bit of luck, I got away with no additional damage... but nearly got killed a few times. Let me emphasize the luck factor there. Cost of repair - $600 (had to convert from air suspension to regular struts) My first Golf blew the rear shocks and the old springs were too weak to keep my rear end off of the bumpstops. Again, I was lucky. Those old Golfs were about 1/4 ton lighter than the current ones and had thick bumpstops with *just* enough give so I also managed to avoid permanent damage. Between noticing the odd handling and hitting the bumpstops was less than a week. Cost or repair - $78 What sort of car are we talking here? That might help me help you better.