3:15 possible (Seville Marathon in February)

Hello folks. Putting my entirely justified imposter syndrome to the side for the moment (i am not an ‘advanced runner’!) I have a question for the community! I’m signed up for the Seville Marathon and trying to gauge whether a 3:15 goal (4:37/km or 7:24/mile) is realistic for me. 16 weeks out.

Some background:

• I’ve never run a marathon before.
• I’m 27, reasonably fit/athletic with a background as a decent middle distance runner in middle school. I’m now averaging about 47 km/week over the last month. Averaging 35km/week over the last 3 months. Have been gradually increasing the load, haven’t had any niggles or in juries.
• Longest run of recent training has been 18 km with a block of 11 km at ~5:15/km, which felt controlled and did not go above Zone 3.
• Recent 5K time trial: 22:30 but didnt think I performed well / just dont think i was ‘up for it’ that day. All time 5k PR is 21:40, 10K 44 mins (both in training a few years ago - have never raced at those distances). I do feel like i could get push for sub 21 mins and 44 mins respectively right now if i were to do these distances in a race environment, right now is probably the fittest i have ever been.
• I track with an Apple Watch Ultra 3 but from now will be using Polar H10 for HM
• ⁠I’m about to start a 16-week marathon block, running 6 days a week (3 easy, 1 long, 1 tempo, 1 intervals), peaking at around 90-95km per week with a longest long run of 34 km. 2-3 days of strength training.
• AWUltra 3 says VO2 max 55.5, Polar says 58

Fully appreciate there is a lot to be said for just focusing on the journey and getting over the line for ones first marathon - but i feel like i will get the most out of the experience if i have a stretch goal as a motivator. I feel very committed to putting myself in the best position possible to achieve whatever that stretch goal ends up being goal - from sticking to the plan, eating well, working on form, fuelling, recovery etc. So with all of that said, does 3:15 seem like a realistic goal or have i overshot it? Obviously HM race would be best indication - say i were to do one 12 weeks out, what time should I be targeting as a sign that 3:15 is possible? Any thoughts would be much appreciated!!! Also keen for any insights into Seville - seems to be flat and fast?