I have an 83 300TD

one of my glow plugs is stripped, it came about half way out, and now it just spins and spins.....from what i can gather, i can chance drilling it out, and hope to not mess anything up (not very likely), or i can pay 2500 bucks to have it taken out (def. not happening)...

so my question is this, luckily (with a little patience) it will still crank, even with the one half way out.....should i worry about changing the rest of the glow plugs? It used to always crank right up, then the glow plug light went out, and the first crank of the day was a tough one....it seems that it is performing exactly the same way now, and i can live with that....

I'd like to change the rest, just b/c i've already bought the new plugs, and i figure the new plugs could help pick up the slack of the busted one, but i'm worried that i will just have more busted ones, leaving me no option but to drill or be drilled, as it were....

also, i've never had a diesel in the winter.....its taking me about 3-4 good long cranks to get it going in 80 degree weather, will it be impossible to start in the winter?

thanks for your help!