How to avoid the huge tunnel at Vienna when travelling from Munich to Budapest by train?

Next month I have to travel from Munich to Budapest by train. The train service (the so-called Railjet) runs quite frequently and is reasonably cheap. There is a problem however. I am pretty claustrophobic and absolutely hate tunnels. Small tunnels (<1 km) are bad enough, but manageable. There is a huge one (>20 km) right in front of Vienna (coming from Munich). Technically speaking this is not one tunnel but a whole system containing the "wienerwald" and the "lainzer" tunnel. Nevertheless they are connected underground so the train runs for almost 10 minutes underground with high speed. I would be very relieved if I could spare myself from this experience (especially because this time I am going to travel there with a toddler and the very last thing I want is a panic attack if the train halts underground due to any kind of disruption). So how can I avoid this? I am interested of taking detours if possible. Another possibility that comes to my mind is getting off of the high speed train at the last station before Vienna and taking a regional train to Vienna Central Station if this regional train does not enter the tunnel. Alternatively I can take the whole trip by bus but as I said I will be with a toddler so I'd prefer the train if I could avoid this tunnel. Any advice is highly appreciated.