If you are really trying to retire early I think you need more equities for an early retirement. You have saved almost $350K a good amount and paid off house is certainly a plus. However, as Chemist suggested it may not be enough for an early retirement but certainly you are in fine shape for a traditional retirement.
Eyeballing your list of funds and assets you have about 30% equities and 70%. From a diversity you are probably fine roughly 1/3 international and decent mix of mostly good funds. If I include the bonds in your target retirement funds, plus CD, saving bonds, you have roughly 200K in fixed income. Now given current interest rates, over the next 15 years you'll be lucky to make 4-5% on these investments and very well may have hard time keeping up with inflation. Assuming you are looking at early retirement as say age 55-56. Your fixed income portions will be worth $350-$400K in today's dollars.
If you (and me) are fortunate the 145K equity may grow at rate of 10% (in line with historical equity gains) at which point your equity position might be worth as much as $600K. So your total assets would be $950K to $1 million Using a 3% inflation rate that amount is only worth $600-$650K in today's dollars. Obviously if we have another decade like the last one stocks won't return nearly this amount of money.
I encourage to use FIRECalc to investigate some possibilities as well as understand the impact of additional 15 years of saving might have. Now how much you need to spend in retirement is up to you and again FIRECalc is great tool.
My gut instinct is that you'll need either step up your saving rate, or take more risks in your portfolio, or possibly both. Of course another perfectly viable option is to plan on working longer. .
