I think you would be OK. You can get going and always expand your water volume of needed. I had to expand the water volume in my 40 gallon qt
tank and simply used an overflow and a return pump with a 40 gallon garbage can. (see pic).
Also will need to do daily or every other day water changes until the cycle catches up with the bioload, so have change water ready.
Feed lightly and siphon out all uneaten food. along with the water changes, you may be ok. If not, I presented you with an option.
If you have not purchased the filter yet, check out the Skilter 400. Thats what I use on my 40 and it does a nice job.