Remember, she's in it for the money. Tell her CLEARLY what you expect and the two of you need to agree. Once that happens, and only after that happens, then forget business and enjoy pleasure.

Find out where she'd like to go and if you take her there (assuming you'd like to go there too) she may be more willing to be flexible with the rates - that's certainly the way I do it.  For example, I'm off to India this weekend, I choose the destination and I've had great trips with the client before so my rate is different than it would be if I was off to Iceland with a complete stranger

Most important thing is to discuss what you both want and agree what's expected before you go.  Will she have any private time?  Do you want time on your own?  Can she check her email?  You don't want any misunderstandings which could spoil the trip for either of you.

Since you have known this provider for awhile and might be considered a regular, do you get a discounted rate now?

I only do overnights with my ATF and typically 2-3 days.  longest was four.  I get a discounted rate but I still pay.  As Carrie says, if she gets to choose then that might change the rate.  Typically I pick the place (Vegas, Dallas, Orlando, New Orleans, Boston) but she picks what we do while we are there.

If I am working, she has the day to do whatever she wants, she has to pay for anything wild she does on her own though.  I suppose she is at my beck and call 24/7 but typically I need my alone time too.  She is free to use the internet if I can use the internet.  I like her to restrict the phone traffic and she does except for her mom (thats ok).

I suppose the last thing is to try to schedule around her time of the month unless you and she just don't care.  I don't always have that luxury and it does limit some of the things you may want to do.

If it works right it should "feel" like boy friend/girl friend.  As someone else said, get the financials out of the way early, do something both of you like and have a great time.

Travel rates are ALWAYS negotiable with someone who already knows you, and has a level of familiarity with you.  I DON'T suggest this for someone you have never seen before.  But if you and the lady already have a comfort level, AND you are taking her somewhere that SHE wants to go, AND you are NOT expecting her to be your sex slave for several days on end, but rather, just a normal amount of intimacy (say no more than a couple of times a day), AND, you are providing nice travel accommodations with all expenses paid, then....

I would generally offer the lady something like what I expect that she earns on a ~4 hour dinner date, or from seeing 2 to 3 short time clients on a daily basis.  

Depending on the lady, her comfort level with you and what services she knows she'll be providing, and the destination and expense and luxury of the travel, this would typically come out to something like $600-1000 a day.  

Don't expect anyone to advertise a rate like this.  It's not out there for everyone.  

Other issues that SHE'LL need to consider, and you should discuss honestly with her:  

Does she have kids, or an SO, or a day job/school schedule that will cause consequences she'll have to deal with.  This will affect the cost to her, and her openness to the general idea of travel with you.

Is SHE going to be an equal partner in setting the non-intimacy trip agenda?  This may be the difference between her viewing this as full time work or a paid vacation with brief interruptions for work.