Dog sitting advice

(Mods: this is not me asking how much to charge but a genuine question to see if other sitters reduce their rates for these situations. Thank you)
I’m a dog sitter and have this regular client who travels a lot so I usually watch their dog once or twice a month. I stay in their house and I am allowed to bring my dog with me. The dog i sit is a chihuahua and super easy to care for. Next month, the family has asked me to sit for 3 weeks while they are in Europe. The biggest challenge about the situation is the driving. Since I bring my dog with, I bring him home before I go to work so he is not in their house while I am not there. So it’s an extra trip before and after work and then living out of someone else’s home for that long, there’s a lot of stuff I would need to bring with me. So the struggle I’m having is how much to charge. I typically charge them $60 a night plus $15-20 the last day if I have to come back after work, which I typically do. I’ve never sat any dog for this long so idk if I should be reducing my nightly cost, giving some sort of discount, or keeping my regular prices. This family does seem well off financially but I still want to be fair as this is my most regular client. TIA!