partner in finance - birthday ideas

Hello everyone, 

I'm currently dating someone in PE and while I'm not in the industry myself, I'm familiar with the working hours. I don't think my partner reads this, but just in case they do, I'm trying to keep things as vague as possible with regard to details. 

I'm spending their birthday with them this year, and they usually end up working the day of thanks to the timing/date on the calendar. I'll be spending around a week with them, so there should be plenty of opportunities for celebration. 

I'm looking for some tips and ideas on how to make the week - especially the day of - special for them, without intruding on their schedule or pigeonholing them into plans in case they have to work or leave abruptly. 

Some ideas I have are:

• surprising them with a cake in a flavor/from a local bakery they like, with candles/lettering. 
• Surprising them with some basic decorations like a banner, maybe balloons, etc. either before they wake up or when they return from work, if they need to go in the day of. They're not one to want to care about the 'gram, but I thought just making a point to celebrate even at home would be thoughtful. Does this one strike you guys as weird/invasive?
• Have a setup ready to go in the event we can't go to dinner that night: a basic white tablecloth, candle, takeout from someplace nice (that they like/want to go to) and a bottle of wine or champagne.  Dinner at home, but still romantic and thoughtful. 
• I'm planning to ask some of my friends to record themselves singing and/or wishing my partner a HBD, and play it for them when I bring out the cake/sing in person. They've stated before that they'd just want a simple dinner with friends/family, so since I can't have a party for them,  I'll bring the party to them. 

I settled on these ideas as examples of celebrating that are thoughtful and above all else, flexible - easily reversed or otherwise not impacted by sudden changes in plans, depending on what happens the day of.  There's other gift ideas I won't get into, but ideas/tips on that are welcome too. My partner makes significantly more than me, as you can imagine, and this does not bother them in the slightest, but more lavish gifts are somewhat pointless as they already have everything they want/can afford much more than I can and usually insist on paying anyway. I'm sure many of you are used to this exact scenario (what DO you give the person that has everything but time?) so any feedback you have is helpful. TIA.