Tank Size Vs Stand

If the furniture is strong enough to support the weight, and the tank's not left anywhere precarious where it could be knocked over, then I don't think it should pose much of a problem. 1cm on either side isn't a massive overhang, but it may mean that the overall weight of tank and water is more than the base unit is intended to carry.

Definitely not worth the risk, Johno2009 - so good call for having subsequently purchased a tank stand.    Having any form of overhang, even less than the 1cm you had on each side, significantly impacts on the tank, weakens it, with either at best a slow leak or at worst a sudden/explosive breakage of the tank and a catastrophic leak.

The new tank, and the stand, (and furthermore its location away from direct sunlight), sound ideal for your fish aspirations. Looking forward to reading and seeing photos once you've finished the cycle and eventually stocked with the fish of your choice.