dont ever, ever hold up ur dreams for a chick. women who are down for u will be excited to follow u wherever u go. i told a story many pages back about an ex that wanted to follow me to another part of the country. she was ready. all she was waiting for was for me to say do it.
in ur case, even if ur girl comes with u, she'll make u feel shytty for "uprooting" her life and will start making impossible demands on u. if ur not careful, that 20k increase in salary will vanish if u have to take care of her responsibilities, out of guilt. unless she has no marketable skills, she should be able to find a job wherever u go.
if shes not down to go where u are, or is hesitant, u need to sit her down and have a serious conversation. "honey, i love u. i moved here for u. now, i have an opportunity to make my/our life better. if u dont come with me, u'll be making a statement that i cant and wont ignore".