I am earning less than that and have (just about) managed to have two preschoolers in full-time daycare. It is very very hard and at times I have had to cut back on food, etc. However, you will definitely be able to afford something on that kind of salary I'd have thought.
Where you might have to change your plans is the thought of a nanny, or how you recruit one. How large is your house? You can pay a nanny a reduced fee if he/she lives in. There are agencies that help those who want to nanny share. Or you could put an ad in the local paper asking for it. Or you could recruit privately. It requires greater effort in the beginning (in terms of thinking about skills/qualities you are looking for, chasing up references and paying for a CRB check, etc) but you can choose just as good a nanny yourself as you can paying an agency if you know what you're doing. And you could choose someone local and unqualified, which could result in a cheaper hourly rate and help you make friends in the community. Also, you could compromise and offer a lower rate in return for helping the nanny to become an OFSTED approved nanny (like a CM), of which there are very few so could add to the nanny's earning potential when he/she moves on from you.
Failing that, why not consider an au pair or a childminder? The flexibility of a CM isn't as great in terms of working hours and you don't have the luxury of them operating in your own home, but it's a thought. It's worked for me.
Ultimately, though, the biggest thing to get right here is your employer. No matter how good your nanny/cm/au pair, without family or friends to step into the breach on days where something goes wrong with your childcare arrangements, you are going to need some goodwill from your employer and an understanding attitude. Although I am worth every penny of my salary and have more than made up for hours off I have taken, I am under no illusions that I would have lost my job a long time ago if my wonderful boss hadn't been so accommodating about time off at short notice because, like you, I am not local and have no family to help.
One last word, as others have already pointed out. Only half the childcare costs are your responsibility. It took two of you to make your children. So while it makes no difference to the overall family budget, it makes a bit difference in how you think about it psychologically and the cost-benefit analysis in terms of your own employment.
Good luck.