Short answer: WTKR would, hands down, with their new graphics and studio investment, and being the only direct competitor during "eyeball getter" primetime and morning news hours.
Long version:
I'm a fan of WVEC's product, and while they appear to be heir apparent (last I checked they were #2 in most slots), they have absolutely no more room to grow in the market. Remember that WAVY and WTKR are the only two stations with extended morning news from 7-9 AND the only two with primetime news (WTKR has a 7pm, and both have a 10pm). WVEC can't compete with either station beyond 7am or in the early evening, because there is nowhere for them to actually go or broadcast. All they really have is the longevity in talent (the longest on air broadcast team in the market at the traditional 5,6 & 11), but if TEGNA keeps cutting senior market folks...they definitely will lose too.
So, if WAVY were to fall from grace. WVEC might win a couple of "traditional" slots at 5, 6 & 11, but WTKR would be the clear cut winner in every other slot. The eyeballs would just migrate to the only other product available in town at those hours --WTKR.
So with TKR has ALL the chips really in their basket.