1999 Mercury Marquis coils

My car was diagnosed with 2 bad coils, she runs ok, just hesitates once in a while she does good on highway but sluggish on roads but stops after a bit. I need t get back to florida from nj, will this be ok to do? My mechanic will fix it in florida, and I was told itll be ok but the fuel economy will be higher than normal until its fixed.