Unless you accepted today, you have now bought yourself another week due to the holiday :)
What are your goals? How much compensation are you hoping for? Have you researched salaries for the role/company/area?
Because it sounds like the recruiter mentioned 125 at the top end, and you and got exactly that! 105+20 bonus!
Do you have any other interviews / offers on the table? Have you applied to other companies?
You can thank the recruiter for the offer, mention how impressed you are with the company, the team, the hiring manager blah blah. Remphasize your value and excitement blah blah. Then you can either mention other pending interviews or expected offers from competing company X, Y and Z. Up to you how far to push this knowing that the worst-case scenario is that they pass. But this is often the only way to maximize your offer.
Once you get closer to accepting, and the company is fully bought in, you can then mention that you still need to give your current employer 2-3 to wrap things up, which would bring you through the holidays. And suggest a start date of Jan 3. Should be no issue. They likely won't want to you start mid-late December anyways.
Check here for salaries for similar roles.
https://www.levels.fyi/https://h1bdata.infoGood luck!
