First, a Class 1 felony is punishable by 4 to 15 years in prison, but is usually eligible for probation. Second, you could be tried and sentenced in your absence. If this happens, the court will issue a warrant for your arrest which will remain until you are picked up. If you are ever stopped for even a minor traffic ticket, you will be arrested on the warrant and extradited back to Illinois to serve your sentence. If you do not address the situation now, you will always be looking over your shoulder. Your new life will mean nothing to the agency executing the warrant. It will also mean nothing to the court which you chose to disobey. Running may delay your problems, but it will solve nothing.
I would not advise you to flee to another state. By fleeing, you not only can pick up a no-bond warrant for your arrest but you can also pick up new criminal charges for fleeing while on bond. If you get pulled over for a traffic violation while in the new state (even ten years from now) you will be held in that state until you can be extradited back to Illinois.
If you have any contact with law enforcement they may have the warrant in the system. If you get arrested the warrant state must decide whether or not to extradite you back which can be a costly process.
First, you cannot receive a two year sentence on a Class 1 felony, so there may be something you do not understand about the charge or sentence. Second, if the sentence is pursuant to a plea bargain, the deal will be revoked and you will be tried and sentenced in your absence, most likely getting the maximum allowable under the law (15 years if indeed you are charged with a Class 1). Additionally, you will be indicted for felony bail jumping and that sentence will run consecutively to whatever you receive on the current charge (you will get the maximum for one class lower that the charge on which you jumped bail). Finally, be advised that interstate flight to avoid prosecution is a federal offense for which you could also be prosecuted.