As long as you want. The longer you drive it, the more damage you can do to certain parts such as the catylitic converter. Not to mention you are wasting gas. Get it fixed as soon as you can.
A long time Until your spark plugs become so saturated with oil that they're no longer able to function. By the way, replacing the valve cover gaskets on a '94 Q45 is no walk in the park. Good luck!
The 2013 Infiniti QX is 17 ft. 4.3 in. (208.3 in.) long.
The 2013 Infiniti M is 16 ft. 2.7 in. (194.7 in.) long.
The 2013 Infiniti FX is 15 ft. 11.3 in. (191.3 in.) long.
The 2011 Infiniti EX is 15 ft. 2.3 in. (182.3 in.) long.
The 2013 Infiniti EX is 15 ft. 2.3 in. (182.3 in.) long.
The 2011 Infiniti FX is 15 ft. 11.3 in. (191.3 in.) long.
The 2012 Infiniti EX is 15 ft. 2.3 in. (182.3 in.) long.
The 2013 Infiniti JX is 16 ft. 4.4 in. (196.4 in.) long.
The 2014 Infiniti QX70 is 15 ft. 11.3 in. (191.3 in.) long.
The 2014 Infiniti Q70 is 16 ft. 2.7 in. (194.7 in.) long.
The 2012 Infiniti M is 16 ft. 2.7 in. (194.7 in.) long.